Did you know you can get free stuff from 3D printing companies just by doing the things you normally would do anyway?
On Bambu Lab's MakerWorld I have gotten free PLA filament and their electronics kits. I have enough on the Prusa equivalent to get some free filament or resin.
To get you started, just completing your user profile gets you a bunch of reward points.
Of course this is all to promote usage and materials within the companies own ecosystems, but as I say we get rewarded for doing things we probably would do already.
The main way I have been rewarded is from uploading 3D models, which I did for years on Thingiverse until it became pretty poop. Now on MakerWorld I get reward points that I can cash in for gift cards.
You don't have to upload models, though, as MakerWorld encourages you to upload tested print profiles to models too. The more people who use your profile to print, the more points you get. Think how many times you downloaded a model or sent something to print but you realised there were better ways to orient or configure the print for speed or quality?