Went through a similar process a few years back.
I found there was no huge value having a beefed up Amiga (030+) for games and games were my main interest. I'd say the HD was the best upgrade, then RAM, AGA and faster CPU not so much, 68882 FPU was a waste of money for me.
Demos are another venue for tooling around with a beefed up Amiga but tend to look a bit quaint out of context.
