I used to stockpile a lot of stuff, now, life is just too short and I buy stuff as I need it most of the time.

When a game comes in for restoration, I make a pretty specific list of the parts I am going to need... then, I start getting them when the deals are good.

When I finish a game, I just pick whatever restoration I am the closest to having all the parts I need for, and I buy the remaining parts and get started.