I have a good amount of factory sealed games in my collection but I never go spending hundreds on them. I either just never got around to opening them(like the majority of my PS1 games) or I got them on the cheap at clearance sales. Theres a few I paid 20-50 for on ebay(16 bit era) but I could always get that back.
Alot of people think the whole point of collecting sealed games is pointless. The way I look at it is that if you have two copies of a game(one sealed and one opened) from this gen or any of the previous six generations, 99% of the time you are going to get a premium for the sealed copy. While it may be only an additional $5 for more common titles, you'd still make more money on the sealed versions. So as long as you are getting the sealed games for a cheap price(clearance sales for example) than you are almost guaranteed to make more money off of it in the future.