Best bang for the buck

Most bang for the buck was a rug to counter the floor sound. However I've switched to e-stat and this is no longer needed. I don't have any other bang for the buck, everything is so expensive.

Hands down, room treatments, all stop.  I've got a fully treated room and finally got around to putting some Rockwool insulation in the crawl space under the floor and got a transformative SQ increase.  $250 well spent.  

@rick_n Have to agree- room treatment is a very high value proposition. When I moved I spent about $1000 on room treatment- incredible 

My speakers cost me close to $1000 in parts to build in 1989, and I've managed to build a system around them that I've loved for decades, and will very likely be with me for life.   Got my money's worth years ago.  

A lot of good deals over the years.  The best bang for the buck are the pair of dipole towers I bought used a few years ago for $100.  Still going strong as Left and Right fronts in a 7.1 system.