I have two of the original Digimon pets that were released sometime in the late '90s. One is blue and the other is yellow. I've seen some of these go for around £40 (around $60) on eBay, but although tempted I'd find it difficult to part from them. I haven't actually used them since I was a kid. I ought to pop a fresh battery in one of them. I have fond memories of battling others' Digimon in my primary school. I remember how awesome it was when my rookie Agumon defeated a friend's Greymon. There was a very rare probability of success, but I did it, and my friend had to start from square one. That was the fun thing about Digimon: risks, and also longevity since there were many Digimon yours could branch towards.