i'll third john's proposal.
i tend to think of it a little differently. for me, it's about longevity vs. technology.
prime example is speakers. for the most part, they haven't changed much in the past 50 years. you still have a driver, in a box, that creates sound. so, i'm willing to spend more money to get speakers that i like, since i'm banking on keeping them for quite a while. i know people who still use the same speakers they've had for 10...even 15 years. heck, even my polks are about seven years old. bottom line, i'm willing to spend more here cuz i know i'm gonna keep them.
electronics change a little more. right now, with hd dvd players, new connections (hdmi/dvi), etc -- you'll see the gear change more. so, i'm not willing to spend quite as much...on the assumption that something new will come out shortly.
cables are a whole different story. you can break the bank with these things. my recommendation is to buy some decent quality (but not outrageously expensive) cables. don't use the cheap ones that come in the box. after all, there's a reason they're free.
anyway you look at it, pioneer/svs/polk is a good combo...i'm pretty sure you'll be happy.