Yes they work, but they work in different degrees. If you are one of the unfortunate souls who has "bad" power, a line conditioner will have a more dramatic effect than for one who has "good" power. A good quality (a very subjective phrase) line conditioner should be in the $400-1000 range, depending on your needs, such as quantity of amps, and other equipment. PS Audio make great products but are much more limited as to how many pieces you can plug into them. I concider CinePro a good piece, also look at Tice, and Chang (maybe even Monster, but demo first!!!). Panamax make a few good ones as well (their early models got good reviews). Check out audioreview.com
