Well maybe you could create a box template that you like, then scan and resize it, and then print them out on card stock paper. You could even design something nice for it.
Card boxes seems like they use 100lb card stock (pronounced 100 pound card stock). You could use 65lb card stock for a thinner box though. Card stock can be a bit tricky to cut and fold, so use an exacto knife and a cutting mat, and then use a ruler to make clean cuts and folds. Some paper cutters/trimmers can do most of the work though. Card stock paper comes in a pack of 250 sheets, and sold for less than $20.
Sometimes card stock can be tricky to print on, so you can test out a sheet to see if it'll run through the printer properly. Some printers are designed to print on heavy weight paper, but others you could try fiddling around with. 65lb card stock would probably run through fine on most printers. And if you have an inkjet printer, make sure to leave it to dry somewhere before trying to handle it.
But if you're tight on cash, maybe buy some bristol board (or poster board). Then you could either print a design on that and cut that out into boxes, or just manually use a pencil trace a template onto the paper and cut and fold that but it won't have a pretty design on it.