Xamarin puts out a quality product, they should charge a price for it relative to the value it can bring a MOTIVATED developer. And if we want to use it we should pay for it. I don't want to wake up tomorrow to see that they dropped the price to 5 bucks hoping to win on volume only to find out soon afterward that Microsoft paid them 25 million to stop development.
As for the paid product, we issue a no-questions-asked refund to anyone who requests it within some reasonable amount of time (30 days usually). Even with this, our refund rate is less than 1%.
E.g.: "Pay only after you earn your first 100$" but along with "NO WARRANTY" and "no support" and maybe "without IDE, only cmd line tools and SDK" but that would be an extreme - still, better than nothing.
I think this will _tremendously_ boost your user base.
All in all, you will cover a new target market with retaining the existing market.
Anyway, thanks for the great product!
EDIT: the market you actually will loose (in "no support" users) - are the users who didn't succeed. Not sure if you can track the numbers, that would help to determine if this business model will be positive for you.
That said, I totally understand if that's not a market Xamarin wants to be in.
Frankly speaking, if 400$ for a product like MonoTouch is risk for you then you probably shouldn't be developing commercial software which you sell for money.
What I have an objection to is the idea of 'pay if I succeed' model. Clearly the OP is not talking about a silly app given away for free. He wants to make money selling software but refuses to pay for tools which can help him create the software faster.
(and using objective C/XCode are pretty much at the bottom of my list of things I ever want to do in my life)
It would also be a good teaser to make me pay the full price once I've used it for a while.
Edit: what is "risk free"?