I usually only get games and stuff through Ebay, and even then I try to get new items. If it was me, I'd only go with Ebay if I desperately wanted a 60gb, but if you're a bit more laid back about these things, then I see no reason not to go through ebay, provided the seller has a 99%+ rating.
Just make sure you get insurance.
Edit: Apparently I missed the fact that it was a 60gb system you are looking for. I say go for it. Full BC is worth it, and you most likely won't find one any other way.