Congrats! You have made something of value that people appreciate. Getting the first paid user is usually the hardest.

I would not sell the project at this stage as you would sell it for not a big value. You would need a couple more paying users to prove your concept.

Once you have a few hundred paying users, you would see interesting data. Like how many months they keep paying? How many of them churn? How much can I afford to pay for acquiring a paying user?