Used vs New vs Vintage vs Floorstanding vs Bookshelf vs ..... OMG!

1. Read. Read reliable solid info like Robert Harley's Complete Guide to High End Audio. Study that book like your life depends on it. Literally decades since my first read and still not a day goes by I don't see questions here that are answered in that book.

2. Disregard. A lot of stuff on the web is dudes with no experience to back up what they nevertheless are quite eager to tell you as if they have a clue when they don't. #1 above will help you separate the wheat from the chaff.

3. Listen. While you are reading up spend as much time as you can listening to as much gear as you can. Pay attention to everything- all the associated components, how they are set up - especially the speakers - the room, even things like do they leave the SS gear on overnight or was it just turned on, are the components on cones and the cables elevated up off the floor and is the system complete or are there stock factory power cords. Even doing this its almost impossible to get a handle on what you're hearing unless you have them swap out some components. So always ask to hear the system with a different power cord, interconnect, speaker cable, etc. This one simple step will massively accelerate your learning curve.

4. Budget. You mention being new and wanting to buy speakers. But why speakers? Its common to place way too much importance on speakers. They are important for sure, but really not much more so than anything else. You will never get good sound without also having very good speaker cables, amp, interconnects, power cords, and a turntable. Beyond that you will be surprised how much an already good system can be improved by "accessories" and "tweaks" like fuses, cones, and other neat stuff. Guess what? Covered in Harley's book! Pretty much everything I'm saying is covered in his book! Including to budget serious money for all the stuff above. 

5. Reality. The $3k speakers you are now up to would be at home in a really sweet $15k system. The other $12k going into all the wire and cones and fuses, etc. Each individual component if bought as above will indeed be an improvement. But the truth is with the right purchases and a synergistic balance of all components you could have a sweet system complete and done for that same $3k. Most never figure this out, instead chase after grail after grail, never getting good results because they spend so much on each grail they never have the money to fill in what is needed to get the most out of the grails.

Its a balancing act with you on the wire and not much of a net below. That's why its best to start with the wire nice and low and practice, practice, practice is better than spend, spend, spend.

Based on my recent speaker shopping experience, some of the older speakers that you are likely to encounter probably are outdated.

I tend to replace my speakers every 10 years. My last speakers were DALI Helicon 400's. They initially retailed for $4500 and had creeped up around $6,000 by the time they were discontinued. So, I assumed I'd need to shop for speakers in the $10,000 range for a significant improvement. Boy was I wrong. 

One of the speakers I auditioned was the new Focal Kanta # 2. I was very impressed with that speaker; but, I didn't think it was quite worth the $10K list price. So, I tried the Focal Electra 1038 BE, which the Kanta is replacing. I found the 1038 BE's to be stunningly disappointing when compared to the Kanta's. Unfortunately, I have not heard their Aria line.

As I continued to shop, I  was very surprised at how good Revel Performa F 206 & 208's sounded @  $3500 & $5000 respectively. So, some speaker brands (perhaps most of them) appear to have taken a large leap in the last 10 years. So, as many others have said, listen to as many speakers as you can. I know it's time consuming and often frustrating; but, I bet your patience will be rewarded

I gotta say, times have changed, and I no longer consider myself an audiophile, at least by the standards here.  When I was a young man, it was all about low distortion amps, at least 100W/ch.  Everyone knew that the speakers introduced more distortion than any good amp would.  Next problem, would be the room.  Third problem would be the limitations and issues with vinyl records.  Now days, it seems like everything is subjective.  Throw some old technology in, like glowing tube amps, crazy speaker designs, all sorts of things that create innacuracies, cost tons, and are full of hype.  Yeah, if you spend $10k on a pair of speakers and amps, you are going to tell yourself they are great, otherwise you are a dope, right?

When it comes to high fidelity speakers, the straightforward engineering and design was done in the three decades from ‘50 to ‘80.  Good bass, square inches of driver.  Efficiency, horns.  Good highs, domes.  Get some of those high end vintage studio monitors from the last decade of that period from Altec Lansing, et al, and you won’t lose money when the marketing hype runs out on those ridiculously expensive systems.  (Full disclosure, I just sold a pair that I got in the mid-seventies, for several times what I paid for them then, and they can still be re-serviced to this day.) Unless of course, you just want to brag about how much you spent to get the exact ‘tone’ (distortion?) you were looking for.  

Now, I wait for the experts to cry foul and my ignorance and naïveté.  Have to admit to both, and am going deaf, so this is now all lost on me.

tykozen,
millercarbon gives you good advice, and I think the most important thing that he said is listen.

A lot of well meaning writers and salespeople and people that you speak to will have strong heartfelt opinions about different brands and types of speakers, but very much like falling in love, when it happens, you’ll know. You may think that you are interested in a large speaker with conventional direct radiating drivers and then one day hear a small electrostatic and discover that it has the sound you’re dreaming of. Nothing you buy will be perfect, but something will give you most of what you want, and the only way to find it is to listen.

Good luck, and enjoy he hunt!...it should be fun.

I formerly worked for a small but respected speaker manufacturer in Australia. (Used speakers made by them are higher than your suggested budget).
Things I'd consider if were I in the market for loudspeakers.

• Cabinet design, the more it sounds hollow and drummy when you rap your knuckles on it, the more energy it will release when your drivers compress air within it in the audible spectrum (bad for accuracy). The cabinet will have it's own resonant frequency. This is where less is more, less uncontrolled noise = more controlled sound. Inert cabinets potentially sound better.
  
• Crossover design. Clever crossover design can produce a good sound, however quality parts in the "recipe" simply confirm that the laws of physics (specifically electronics) cannot be denied.
• Drivers that work well with each other, after all the drivers will be fed specific frequencies from the crossover, the exchange or frequencies where two or more drivers are both providing the same notes (the crossover point) is important. Drivers that match each other in where they perform together within their frequency range is very important.
  
• Synergy of all of these elements and more are something your ears (and personal tastes), will tell you. How they sound in the room, the electronics connected to them, cables..the list goes on.