Very neat project. How are you dealing with FCC certification?
The compromise vs "buy some spectrum for 8 trillion dollars" is that you can't use ham radio for commercial (or musical) purposes.
Not sure if you mean building or designing and building. But QRP labs has some nice kits.
Now, in doing so, you're also taking responsibility for your emissions, and you're expected to be diligent about making sure everything is within the rules. But there's no paperwork or anything unless you want there to be. (Taking notes about your spectral purity testing is probably a good idea, you'll probably never need them, but if someone complains it'll be nice to have.)