Amps - New vs. Used


Looking to upgrade amplification from my AVR + a 2 channel outboard running the mains. I also have a powered sub, Hsu ULS15.

Am I better off to get a 'higher quality' used setup (be it a 7 channel or combination of multiple amps), or buy new amps?

I'm wondering about the changes in designs, performance, reliability that may have occured in the last decade or so. I have no problem buying good used equipment, I like to get the most bang-for-buck, obviously, and used has the potential to increase that quotient.

I don't have a set budget, I prefer to wait a little longer if necessary to get what I'll really want, but lets' keep it in the $2-3K range. EBay always seems to have options that seem good in the sub $2K range.

Room is a 12X19X8 rectangle, my 125wpc Yamaha struggles when I wind up my low-efficiency speakers, (86db?) but the newly added sub helps. There is a speaker upgrade in the future too. Which brings up a part-2 to the question, should I upgrade my mains first, then worry about amps?

Thanks
english210
I would get your mains situation figured out first. If your next upgrade is higher in efficiency or load you may be able to live with the current amplification a while longer and save more money to get a better amp. At that point you will know the character of the new speakers (bright, dark, fast, neutral etc), which sound more different compared to each other than most amps sound different at the same price level.
Great, thanks for the thoughts. So it sounds like good used (B&K is only radar, along with Parasound, ATI, Emotiva, Outlaw) is only slightly more risky than new, and potentially cheaper, with one vote to upgrade amps first and see if that satisfies, and one vote for new mains which may satisfy, but if not, then I can shop for the amp with the sound to best match the upgraded mains. I have been looking hard at Synchrony's or maybe Imagine T2's. I must say I'm more nervous about buying speakers without an audition than I am amps. Thanks, keep suggestions coming...:)
Tell us a little more about what you listen to and what elements of music
reproduction you value most. This will keep us from recommending a dark
laid back speaker to someone who looks for speed and dynamics.

Nothing beats personal experience. Try to make time to get out and listen
to as many potential candidates as possible. Read reviews. While not the
last word in finding truth you will see some patterns develop as to what
different components sound like and what traits they generally have.
Knowledge is power!
You can buy a brand new Theta Intrepid 5 channel amp on AudiogoN for $1,500 and be done with it.
I just added a sub, and was really happy to hear more 'air' around instruments in the highs in my main speakers than before. A particular trumpet note that 'rang' after the note ended that I'd never heard before stood out. But at the same time, the highs were too bright in other material, and it was fatiguing. Music tastes are varied, from Pink Floyd to Jennifer Warnes, Casting Crowns to Dire Straits. A wide, deep, focused soundstage, the afore-mentioned air, and a tight but full bodied bass. That's the best I can describe.

Ok, I'll look at that Theta too, thanks