Indeed no, I do not think it is right to develop in an open source platform, then expect people to buy your utility that could have been made by anyone with the same end use need.
I have no problem paying someone 99 cents to do that particular bit of work for me. I don't want to take the time to either learn the code or then write the app. I appreciate the free apps, but I have no problem with anyone wanting to get paid for what they have to offer. I can decide whether I want to pay for it or not.