I bought a frame this weekend from a very nice guy who was going through something like this--he was trying to get down to 10 bikes. He had 7 custom frames built for him, so those were staying. He needed to figure out which 3 others he was going to keep. The 1983 Trek 600 I bought didn't make the cut.

Maybe you should do the same? Evaluate which bikes you ride a lot for one reason or another, which ones you couldn't possibly part with because they're so special, and start selling the rest?