My guess would be more like 50-60 collectors who regularly add $100 chips to their collections.

I don't collect regular issue chips currently in play except for baccarat chips. Have about 35 baccarat $100's, as well as all the hundreds I can find from Harrahs Reno/Tahoe, Golden Nugget, Aladdin, and the three Saharas, maybe 15-20 more.