M.D.
I always (and still do) donate my kids things. There are people out there who need things and if I can afford to donate, I do. Now if I couldn't I'd sell. But if you can afford to donate them to someone in need, maybe consider doing that.
I'd also put a low price on them. They are 5 years old and even if they are in like-new condition, people looking to buy used wouldn't pay half of what you paid. If they wanted to do that, they would go buy a cheaper brand new set. So I'd not put it for more than $150 for the set...and that might be pushing it.