This is a bad idea. Never prototype. Make. If you prototype too well, you'll be surprised how often the prototype becomes the application. And then the people who have to maintain the codebase will wonder why so many shortcuts were taken. Why? "It's just a prototype." Or at least it was...

Just don't do it. If REALbasic fits your needs, great. Plenty of people have built giant businesses on the back of Visual Basic applications -- heck, I'm working at one now. No reason not to use REAL to do the same -- heck, you'll pick up another 3% of the market for free (more like another 96% of the market for $200; if you're using REAL you're likely on a Mac) using RB! But don't pretend you're making a prototype. Build it for real, and keep your "dream goals" in mind for version 2 or 3. They'll change anyhow.