i too wanted to purchase 5-6 3D printers and start a business - basically my version of goose farming after i leave the software dev space for the greater good of mankind :)
The card stands were a lot of fun, but most of what I print now are dog toys and gifts for my niece and nephew. It's nice to roll up to a family holiday, and have something interesting and unique you can just hand out.
You could get started doing that for just a couple hundred bucks and some desk space!