I have tried to sell a brand new one before. I got $120 shipped to Illinois. I don't think I netted $100 on the deal. I have two more sitting in my garage. Not even worth cleaning up to try to sell. They take forever to heat up but do OK once they do heat up. But, I MUCH prefer propane over electric.
I tried marketing the electric I sold to condos and apartment dwellers, but I got no bites. It seems to me that most around here don't even allow electric grills near the apartments or condos.
By the way, Weber makes a Q140/1400 and a Q240/2400 and I expect the one you saw was the Q2400 for $300 plus. I don't know their actual retail prices, but one of the ones I have, I bought at Home Depot in the middle of winter on year. It was a Q140 display model they were trying to unload and I picked it up for $65.00