Ask HN: Someone offered to buy my browser extension from me. What now?

I received an offer from a company to buy a popular chrome extension that I created. Any tips to make the transaction extra smooth? Any tips to protect the extension's userbase? This will be an international transaction. The amount is not a lot but also not little.

The escrow sites that I researched all seem really shady. It seems like a paypal to paypal transaction, possibly in two chunks, might be the best. Advice?