I take the approach of some of the other posters. I sell gear I don't use and use that money to buy gear I want to use. Also, I trade studio time for gear. Recently, I aquired a PTHD2 Accel with (2) 192's for X number of studio days.

Also, some great gear I have here is actually not mine, but is kept here for years because I am the only engineer the gear owner will work with, so they just leave it here!