POWER: conditioners vs filters vs cords

OK. I've heard a lot of contradictory stuff on power accesories. I'm going to throw this out to the roundtable and hopefully clear up some of the fog. I've heard the following: 1) Most full blown conditioners ($500+) do everything better. They stabilize input power, clean up ground loops, filter noise and insulate against power surges. However, some compress dynamics. 2) Most surge supressor/filter units ($200-$350) clean up ground loops, filter noise and insulate against power surges. (but a good power conditioner makes the system sound better overall) 3) Good power cords kinda clean-up ground loops and kinda filter noise; their major advantage is a blacker background, better dynamics, soundstage and imaging. 4) If you have a full blown conditioner, better powercords are redundant and offer little advantage. Am I on the right wavelength here? I have a minor intermittent ground loop, and I know my power is a bit on the dirty side, infrasonic garbage wise. So the question is this: I want to improve my sound quality by cleaning up my power supply without blowing a small fortune. I'd like to invest between $200 to $400(list price) but I wouldn't be adverse to bumping the price to $650 if it REALLY makes a difference. What do you recommend? Your opinions on any part of this subject are welcome and product recommendations would be appreciated. Thanks, Morbius2130aol