You could probably get brand-spanking-new for around the same price if you shop around, but I could be wrong there.
However... I've read posts by lots of people on various forums about buying the used phones and everyone seems happy. Some of them have stuck pixel problems (which is likely the reason for the return) which are easily fixed with stuck pixel fixer videos on youtube and such, so I see no reason to NOT buy one used so long as it has a warranty.