I'll play! I think the reason people put down deposit money or pay in full for pre-production game is basically FOMO, fear of missing out. Limited runs of games and many people don't want to left out.

I don't think there is money to be made flipping. Other than maybe a new ACDC Bible. I think people just want to get something new an shiny and get it first. So many buyers are home users. Plenty are on pinside. They want to get the game early, talk about it, complain about all the defects, and mod it up. Money is not always an issue for many of these collectors.