capacitors

My experience suggests changing out loudspeaker caps first is biggest bang for buck. Don't listen to the naysayers, changing out caps can result in great improvements.

As far as cost, the best is going to cost dearly, lots of choices at lower price points. You need to determine which caps are presently used, what sonic improvements you're looking for and budget.

With that budget for those size capacitors I don't think you'll find happiness. The best quality, relatively low priced caps I've heard are the Jantzen Z-Superior copper caps, $44 a piece in 10uf value. Available at partsexpress.com