I’ve got a dozen ideas for inventions that I could knock out quickly with a 3D printer. Note to self, find access to one...
The good SLA versions are about 3-5 grand, they use a resin instead of abs, That is what the guys that made the ar15 lowers used, not the ABS inkjet type, which are only $500
If you are handy building things, the RepRap project may be for you. RepRaps are the cheapest, (but lowest print quality) of any 3D printer. They are built from scratch. They have a side goal of trying to be as fully self reproduceable as possible. This means that a RepRap printer is designed to be created from RepRap printed parts. A RepRap printer can build about 75% of the parts for the RepRap printers, only things like the electronics need to be bought. So once you have one RepRap, you can keep building others.
If you don't want to do that, there are several models less than $2000 now.