How do you determine how much to spend on speakers

I revamped my system incrementally, assuming a $5k budget, over two years. I had a beefy old NAD receiver, a slightly modded Rotel 855 CDP, and DIY (Boston Acoustic designer help) 2 ways from Peerless drivers. Sounded fine for years.
I tried designing a three-way, but got too frustrated, so started the hunt. Knowing the critical nature of room-loading a transducer, I decided to find the best speaker I could IN MY ROOM. Started with Paradigm Powered Monitor, then Thiel 2.3, then Ariel 7b, then JM Labs 820 (?), then B&W803N. Finally I tried the speaker I'll live with forever.
Cost me $8k wholesale. I cried when I heard them.
Dealer told me to get a cleaner amp (especially pre) to drive them. Lots of buzz for the Audio Refinement Complete Integrated at the time. I borrowed one, and was astounded at how more musical and CLEANER it was than the NAD. Not enough powerm, though. Dealer recommended Alephs with these speakers. So I found used Aleph 2s. Now I could REALLY hear the noise and grit upstream! Auditions between ADCOM GFP750 and Aleph P proved doubtless that Nelson's REAL iteration was the way to go, despite cousin Wes's lauding of the ADCOM.
So that left the front end...which was actually the hardest part. Trials of Bel Canto, Arcam 9, Audio Refinement CD, Planet proved to be less musical than my old lowly Rotel!
How could this be? I added a Neuance under the Rotel, and now was even more amazed at how a 10yr old CDP could boogie.
Yet the digititis and glare were all way too much. Yet the Bel Canto needed a dimmer up top, and the ARCAM danced with two left feet...the ARC put me to sleep.
So I stuck my friggin neck out and bought a new EMC-1 with something called a 24/192 MkII DAC at cost from a Danish dealer. My God...I'm done. Ok, I'm still screwing around with cables, and I had to buy a new tuner, after all, and make my own dedicated lines and PCs (thanks, Sean, et al).
So the $5k budget grew to about $18 by the end...for $30k retail value.
Took two years to do, and I had to learn a lot.
One mentor/dealer now flew the bricks n' mortar coop and works for Lenbrook. I remember he once whispered something like "vinyl" at the beginning. But Redbook now sounds SO good I'm selling my AR table and not even thinking about SACD, nevermind DVD-A or combi-players. And boy am I buying CDs on sale!
Thanks, guys, for all the help.
Hope this helps the threadhead.
In a nutshell: find transducers that you fall in love with while auditioning with appropriately neutral electronics.
Then match the electronics and cables to the power and spectral requirements of your system as you deem satisfying musically.
The NAD receiver and 2 ways do nice duty in the family-room HT system. But what a difference!
Good luck.

Listen to lots of live music, then start demoing speakers that are attractive to you IN YOUR ROOM! After all, you have to live with them, even you, like most of us, listen with eyes closed and lights dimmed. Start creeping up in price, continuing to redemo the previous favorite, until you arrive at a price/performance pair you really like.
In my 2 ch ref system this took a year, starting with my vestigial home-made 2-ways through Paradigm Monitors, Thiels, Aeriels, 803N, Fidelios, and finally a demo pair of Parsifal Encores. Ok, that was a quite unrealistic path for most folks, but I'm into these for life (I'm 51, and we FrancoAmericans die young.)....
The second recent go-around concerned our HT system, where I demoed a bunch of 5.1 sub/sat systems, eventually going for the honest midrange of an affordable ($1400) Spendor S3/1p +SC3 front trio. For Ellen's kitchen system the $199 Onkyo CR305TX minisystem, bookshelf-mounted, was a no-brainer. Likewise a leftover pair of Polk whatevers from two years ago serves the bedroom TV exceptionally well.
Hope you're getting my drift. You set your musical priorities and go from there. I always start with the best transducer-in-the-room (loudspeaker), given the source(s), and then amplify appropriately. Cheap Canare Star-Quad cabling is great, except for the 2ch ref system. Try to be really patient, listening objectively. Sometimes reading while listening, or listening from an adjacent room will give you indirect cues that otherwise aren't recognized because you're trying to get analytical. Females are very helpful for sorting out upper octave stuff, too. (My 17yr old daughter speeds up my Steinway treble voicing immeasurably. Same with interconnect and my DIY PCKit comparos.) I just realized that this thread is TWO YEARS OLD!...Happy New Year AGAIN everybody.