I OWN a number of games that are worth more now than when I paid for them - particularly RPGs - but that's mere happenstance that I was into RPGs during specific time frames (SNES and PSX).
If the game is good enough, I can warrant the purchase, regardless of "collecting." As far as controllers, I've paid more than $300 for at least three different controllers (one of which was technically a set of three purchases), and a $100 or more for a number more. For a few years I've had my eye on a controller that would cost me over $1000, but that's one hell of a rainy day purchase. My wife would kill me.
And for the reference, I also have two kids. They're going to love some of this stuff when they're older.