Don't you love it when you ask a simple question and most of these people don't answer your question?
If I wanted to buy a power conditioner my 1st choice would be the Shunyata Denali 6000/S v2. They just came out with this new model and two friends of mine bought one and they both had the "older" model and they raved about the older model. They both claim that this newer model is significantly better. One friend owns an Ayre stereo amplifier (I'm not sure which one) that he bought a few years ago and has been very happy with it. He has been upgrading his system in the last few years and has improved his system to the point of where he now now feels the Ayre amp is his weak link. He was planning on upgrading it. He has a very nice system. When he plugged the Ayre amp into the new Denali conditioner he said it was so good that he no longer feels the need to upgrade the amp anymore. The Denali 6000/S v2 retails for $5000.00 which I know is out of your budget but you may want to consider stretching the budget if possible.
The other model that gets tons of great reviews is the Audioquest Niagara 5000, unfortunately this one also sells for $5000.00 but you can find these used all the time for $2500.00 to $3000.00. You may also be interested in the older Denali 6000 model as these are starting to be seen in the used market as well because of the new model.
The cool thing about a conditioner is, when you buy a better preamp, you have improved one piece of equipment, when you buy a power conditioner, you improve every piece of equipment in your system. Pretty cool. Good luck with whatever you choose to do.