In some cases I would agree with you Chris - there are quite a few people out there that expect the world for $25.
But...... when you make the decision to become a vendor (third party developer) then you accept the responsibility for support and dealing with sometimes difficult customers no matter what you charge for your product. This is the same no matter what business you enter into. The good thing is that most normal customers don't expect the world - they just expect you to be professional, return your emails (at least the first few and if you're too dense to get it after that then shame on you), and maybe test your product to make sure it is not going to crash entire systems before you release it. Not too demanding. And.... most developers I have dealt with have been very professional and even went beyond my expectations. i.e. Kelly Ford @ Xmod, Richard @ dnnstuff.com, Scott @ Ventrian, are just a couple of examples I have personally dealt with.
So I would say, overall, that most third party DNN developers are very professional and offer excellent support. This is what makes the bad ones stand out even further - once you have experienced good customer service you begin to expect it. And if I remember correctly the bad developers are one of the main reasons DNN came out with their module review process?
Greg