Are you talking about an active crossover? A good active crossover will certainly help if you really want to bi-amp, but they're not cheap. Most speakers that are bi-amp-capable have their own internal passive crossover hardware, though, so it's not absolutely necessary.
Yeah, the only reason to bi-wire is if you're using low-quality and/or thin-carrier speaker wire. If you're already using halfway decent speaker wire that's the proper gauge for the length of the run it does absolutely nothing.
I'm sure that CCNA knows what he's talking about, but be careful about trusting just anyone that calls themselves an "audiophile." The majority of people calling themselves "audiophiles" that I've spoken with about audio have had no idea what they were talking about. Maybe it's just me, but people tend to throw that term around a bit liberally. I mean, we all like pretty sounds, right?
A friend of mine used to work at a local audio/electronics place that's pretty well known around here (called "Abt"). He always used to say that when someone came in to the audio department and called themselves an "audiophile" he saw commission dollar signs. It usually meant that they'd be easy to talk into spending a lot of money on expensive placebos that they didn't need. The "real" audio enthusiasts were more difficult to sell on things, because they usually came in knowing what they wanted and were less likely to fall for a sales pitch.
What kind of speakers are you using? You can get some really good deals on some fantastic amplifiers if you don't mind buying a used one. The technology of making speakers sound good (for stereo music, anyway) hasn't changed much over the past couple of decades, so if you're smart you can find a high-end amp for a tenth of what it cost new and end up with a seriously nice-sounding set up without dropping thousands of dollars. You'll want to pick an amp that pairs well with your speakers, though. Different amps tend to favor different sound characteristics (and so do speakers), so a good place to start is to find out which amps balance well with your speakers.