PULL!!! BMC SKEET SHOOT...jk, looks like hes done quite a bit of collecting, and would like a return on it....go for it, sounds good...or nominate for the best of craigslist.
( for the right person it looks perfect)
People will collect just about anything and there is definitely a market for beer steins. The biggest problem is he is unwilling to sell it piece-wise, because 99% of collecting is the hunt. Few people will want a "ready-made" collection.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk