I just buy up things in bulk lots on ebay, and I guess just horde cheap players so I will always have a backup just in case something breaks. Plus, my friends know I collect units and discs, and a couple have even bought stuff for me, or found boxes of discs stored and sent them my way to 'give to a good home'. Sure, it's nice to have the coveted units, but if you think in a mindset of hypothetical apocalypse, then you'll be able to make use of and enjoy what you have.
Also, the R700 you have is a very nice shade of green. So beautiful.