Well, speaking only for myself, I have in the past for a different hobby been in a situation where I have been looking for a certain item, in a certain condition, for a certain reason, for a very long time. When one finally comes up that is just right, I don't mind bidding more than it is worth, to finally get it. So, in those rare instances, I don't mind spending an extra $100 for something.
I note that many folks on this board love trains so much that they will drop a $1,000 on an engine they want. So, really, what is an extra $100? You are not buying it to sell, you are buying it to run or to finally complete a long open project. And, if you buy a rare item in a high quality condition, and pay too much, then typically, in 4 years or so, it has increased in value to the price you paid.
Mannyrock