Also if you need the STL Yeggi is a great resource to find free models. It searches a number of data bases that are pay or free.
https://cults3d.com/en/3d-model/game/m1-garand is an STL you have to pay for
https://www.thingiverse.com/thing:1729635 is a free STL
Lots can go into the cost of the print but raw materials shouldn't be more than a roll of filament (40$). We have a 3D printer but the print bed can only handle 22cm x 22 cm x 25 cm so the scale of this wouldnt work!