[petervandijck]

If you're somewhat interested, first, negotiate. Make them understand that this won't be cheap. They have likely decided that this way (acquiring + salary) is cheaper than building it themselves, and they're likely offering you a lot less than they are willing to pay.

1. double the price (from, say, 150,000 US to 300,000 US, or from 500 to 1,000). Just double it. Really. You can always go down.

2. Ask for a guaranteed yearly salary of 150,000 to 200,000 US$, with benefits. This is not too much.

Then see how they respond.

As for the hiring: make sure they are responsible for getting the visas. I don't think they should be able to see the full source code in advance, it is quite possible that they are just trying to steal your ideas.

[throwaway_123]

Thanks, doubling the price seems logical.

Any more opinions on the yearly salary -- is 150 to 200k an acceptable amount to ask for?

PS: Collectively thank you all for your great comments! They help me a lot clearing things up.