Quoted from Taxman:I'm actually surprised he does not have more. I bump into him in the repair threads for older games more than anywhere else. (now his wish list reads like and IPDB dump)
Space is the main limiting factor, unfortunately. 
You're not to far off about IPDB, though. I do like to rummage around on IPDB...there's all sorts of hidden and lesser known gems kicking around outside of the top 100. They usually get passed over when they come up for sale since everyone makes a beeline for the T2's, BK's, etc.
I also like to read, research, and contribute frequently to pinwiki and IPDB. Just the other day, stumbled upon some info about a game named Gottlieb Zorro that never went into production and wasn't listed on IPDB, so I forwarded on what I found. It looks like the entry was just added today for it with some additional info from Steve @ PBR.
http://www.ipdb.org/machine.cgi?id=6412