This seems like a good answer. I would add that you should be somewhat tactful until you have a suggestion of terms. The "give us a number" doesn't seem serious

This seems like a good answer. I would add that you should be somewhat tactful until you have a suggestion of terms. The "give us a number" doesn't seem serious and it would be wise not to release financials, code and strategy until things become serious and it is evident they are negotiating in good faith. edit: I had a total brain malfunction as pointed out below. Do not be candid, use skepticism and protect your private information.