I got my self recently my first and the cheapest 3D printer I ever seen. And yes I know that it doesn't sound very promising but you have to start somewhere.
https://www.ebay.co.uk/itm/Steadytec...e/273944975924

I noticed that it can use only PLA but why is that?
Is it just the lack of heated bed?

By the way can you safely submerge a object from PLA in a mineral oil? xD