3d printed lasers?

I've heard of prototyping and 3d printing before but had no clue that it's actually something you and I can use.

http://formlabs.com/company/about-us/

Always thought it was more for the commercial market.

Well here they are giving away actual plans to make your own lasers!

https://pinshape.com/items/16919-3d-printed-cross-laser-pointer

Has anyone ever tried this? Like 3d printing your own laser guns or pointers?

Please don't tell me that this is some super expensive thing to get into. I would love to design my own :)