This is the worst I have seen. In the past I have been proposed around 1000$ but this wins, hands down!
The world is getting crowded of last minute entrepreneurs...
I am still using XCode3. Version 4 is pretty buggy and unstable to me. And the transition is not seamless.
Once I tried to put a project on dropbox and worked alternatively with version 3 and 4. A mess.
I will stick to 3 until 4 gets more stable.
If you are asking this question there is more than a chance that you like flash/flex. If they built their tool on top of flash there is more than a chance they like it.
Hence, you are meant for each other!
I wouldn't be concerned about technology issues. If tomorrow flash dies the company will probably explore news ways, new tools. But at that time you will probably have met great friends and colleagues. I think it is more important to focus on the people you work with, rather than the technology you/they use.