500 games sounds like a dream come true lol. I'm not in the US, and I live in a small town, so those things are a little hard to find. Still, I appreciate your advice, sounds like a good strategy!
Honestly, for the longest time I was going to go for a complete set of NES games, but once Stadium Events sky rocketed in price, I basically gave up. To think that I could have bought it for around $200 less than 15 years ago and now it's a 10,000+ dollar game!
I figured you weren't from the U.S., since you mentioned RGB. If there is something like craigslist in your area, buy up a want to buy vintage video games ad.
That's pretty much the only strategy for saving lots of money on games. Buy large lots for as cheap as possible and resell your extras on Ebay for as much as possible. lol I know it's a douchey strategy, but it's basically what everyone in the collecting business does.
I've actually moved on from collecting console games, and now collect coin operated arcade cabinets. There is something about having all of your favorite games from the 80/90's in their true arcade form that is very nostalgic for me.