I know just the question is a bit of heresey, but I'm curious...
Sure, there are the express editions. But when Microsoft is effectively competing for 'hearts and minds' in an OSS world, it seems more than a bit counterproductive to charge devs who wholeheartedly support .NET high subscription fees for Microsoft software. It's hard to imagine that, in the context of Microsoft's overall sales, dev licenses represent such a significant revenue stream as to justify the downsides.
So my question is: do you know of any instances where MSDN subscription rates have deterred a team from adopting .NET for a project - where cost played a role in a decision to go OSS instead?