Has anyone...

[Ultraman]

I can't say I've ever made anything with QB64 that I've sold, mainly because I don't see it being a good enough language to make anything that someone wouldn't be embarrassed to try to sell. I have used it for making applications that have been used in a production environment by multiple users for completing tasks in a warehouse such as printing barcode labels in extremely large quantities, generating printable reports from EDI documents, and handling asset management. It works great for something like that, when you might be the only person maintaining it. If you were to plan on letting someone else take over from where you left off, use an actual programming language so they're not left confused by the mess you've created. If you're making some game (which, frankly, is all people ever use QB64 for), I could see you getting some dollars out of it. If you're making "software", no. I'd be more forgiving of a game that is unoptimized and fraught with bugs that I spent $2.99 on. If I pay any money for a "software", it better work since it is doing something important. I can't say I've used anything written by someone in QB64 that I'd feel comfortable paying money for. Not even my own creations. That's why I do open-source projects.