I am a little tempted to collect some of that old, but cheap gear. I had a Yamaha SHS-10 keytar years ago and I regret selling that as it was fun. I saw some go for silly prices even though it's not really anything special. I would quite like one of the Casio 'guitar synths' as I lusted after one when they came out. I'll look out for bargains.
!BEER
Yeah - music gear does on the whole eventually get valuable. But the ones that will become true classics are harder to predict. I do have a vintage Roland monosynth, though it's not in good condition (I bought it second hand when I was young and it was already battered). There are some toys I had when I was young that I probably should have held onto though as they are worth a lot now!
!PIZZA