Wouldn't mind building up a collection of arcades myself one day, but judging by the popularity of arcades these days, they may become VERY expensive by then.
If you've got the money, now is the time to buy. Game prices are way down unless it's a rare, popular game.
There's a lot of games for sale in southern Fla. and Georgia right now.
Look on eBay if you want to pay high prices. Craigslist and the arcade game forums are your friends if you want to find some good deals.
Good luck!
-JM