First I would like to state that amplification is important and spending $5k on speakers and driving them with a $500 amplifier (any $500 amp) does not make a whole lot of sense.
If you can afford $5k for speakers now, and will be able to afford to spend $2k+ on an amp in the very near future, that is fine. But if you want to spend $5k on speakers now (using a $500 or so amp), and in a year or so spend $2k+ on an amp, you would MOST LIKELY BE BETTER OFF GETTING $3K SPEAKERS NOW AND SPENDING AORUND $2K ON AN AMP TO MATCH THEM NOW.
Besides component matching, there is such thing as component balance. Nice transparent $5k speakers are going to force you to hear the limits of the upstream components driving them (especially when one has so-so components upstream). Just as mating a world class amp with a middle of the road speaker that the amp can easily drive, you will seriously start hearing the limits of that speaker. This is another reason it is not always good to start with getting a great amp first with middle of the road speakers. Some speakers do not really show their limits or serious flaws until they have an amp driving them that can totally dominate them. These speakers can potentially have resonances that appear, their bass can sound well... not-so-good (trying to reach frequencies that the amp is completely solid to but the speaker was never intened to read), the trebble can start sounding harsh... Whatever minor problems the speaker had in a middle of the road system are amplified many fold when being driven by a great amp (that can drive the speaker well).
Now I am not going to say that all middle of the road speakers will demonstrate fatal flaws when hooked up to nice amplification, but they can, and I have experienced these situations first hand with several older speakers I have owned.
A person is far better off selecting a speaker they love (soundwise), and matching an amp to it (maybe the amp that they heard the speaker on?). Then a person who goes out and buys a great amp and then makes a speaker decision.
Personally, IMHO, there are many more great amps in the world than great preamps. I think most sound in the upstream components gets negatively impacted by the preamplification. If your amp is capable of driving your speakers, besides your speakers, I think the preamp makes the biggest impact on a system. This may seem difficult to understand for the relatively new audiophile, and it has taken me nearly 16 years to come to this conclusion. The preamps should be the ONLY device that regulates/filters sound in a music system. This regulation/filtration is of the absolute utmost importance because what signal gets through the preamp is the ONLY signal that an amplifier can amplify. Bad preamplification can screw up world class sources. Bad preamplification can make a world class amp sound veiled. Bad preamplification can make world class speakers sound anything but world class.
Most people do not put enough emphisis on a preamp because nearly any preamp can seemingly work in any system (this is absolutely not true, but some people passively believe it). As opposed to amps... not every amp can drive any speakers well (most people know this).
Anyway, this and $2 will get you a cofee at Starbucks.
KF