Upload & Sell: Off
I'd sell the refurbished. Per my experience, people who are in the used market are those who don't care much about warranty (if they did, they would have bought new). So, they're more interested in the lower price than anything else. Extended warranty is a nice extra to have, but your potential buyers aren't gonna give you that much value on it. Boosting the price up for $50 is probably the best you're looking at. For that reason, I'll just keep the one with the warranty.