Having said that, do you really think the "pay what you want" is the best pricing model for you?
For me when faced with this model, I always worry that I am paying too little or too much and often don't do it at all. It feels like a donation. While having a fixed price allows me to use my cost-benefit analysis which guides my reasoning.
Also, programmers always seem to have this fear of asking for money for their services. Why is that?