I tend to buy things used if I can save a significant amount of money. Ebay and Etsy are my preferred places for scoring used gear. One tip, though: don't buy from anyone who has a feedback rating below 99% positive. If possible, go for people with 99.5% of higher. And read the negative reviews if you can, because sometimes it's obvious the person leaving the review is just being unreasonable, while other times it can show you a potential major issue.
I'm not a fan of buying anything expensive that has the potential to have hidden problems (like any kind of electronics). I mean, if it was a really, really good deal I might take a chance, but only if I could afford to have it not work.