Worth it to buy cheap, but no audition integrated

I would suggest tubes even if you didn't have bright sounding speakers. I don't know whether you are up to it, but you could try a kit like the DIYCable Ella (http://www.diycable.com/ella.htm).

There are also affordable tube integrated amps here and on e-bay.

I hope you're kidding about "nothing wrong with that mini-system", your right though, there is nothing wrong with it, but instead it does nothing right. I'm not getting into tubes right away, I simply don't want to go used with the risk of getting bad tubes, which I know wear down much more rapidly than ss designs.

Now the question, what CD player? Roksan Kandy, or rega planet, ore creek mk43 2

Audio refinement complete integrated and cdp would be a terrific combo in your range.

I have, way more often than not, auditioned high price stuff, and found it not to work as well in my system because it wasn't a good match. You can waste a lot of meney buying blind. I'm not saying you will, but if you wanted to spend a lot of money and not like the way it sounds, that is the best formula. There are a lot of components out there, and evan VERY expensive ones, that sound terrible in the wrong context, and a lot that you just won't like, because of your preferences, and a respected reviewers preferences are no better than yours.
One of the things that makes what we call "high end" just that, is component matching and synergy between components. It is almost a guarrentee that a less expensive component working its best will outperform an expensive component working at its worst. Also, I would like to add that evan though I find reviews helpful in choosing which components I think I would like, more often than not (way more) the component would sound different than what I thought, evan as I might find the particular review accurate after listening for myself.
The one exception I would make is if you had a particular component with which there was a particular, well known match, a pair or group of components that had a reputation for working well together, but this is far more rare than not.
I think you would get far better value looking and auditioning amplifiers that cost 500$ than to buy something used for 500$ that cost 1000$ new, especially amp/speaker combos. there are a lot of good recomendations on this post as far as good amps for the money, and which work better than others, but guys, what are your experiences auditioning or buying blind?