Hi:
I know the first time this happens it always comes along with a great amount of "guilt". Just make sure you ship the item with tracking and insurance because there is a very good chance that your buyer is going to regret paying that much for it after he/she has a couple of days to think about it. They may try to file an "item not as described" or worse yet a chargeback.
I once sold a child's used dress (it had a bus pattern on it) for $50. I paid $2 for it at the local goodwill and only bought it because I figured it might be a great back to school item. I was hoping to get about $10 for it. My customer was very pleased with it and there were no regrets but I worried for a long time that there might be.
On the bright side, congrats on the great profits :)
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