i make bad posture too and i got about 2 big sketch books from ross that were about 10-20 maybe for one of them or both? but i was able to pay w/ my allowance that's basically 20
I have 2 small pro art sketch books and I almost filled up the first one (I lost it 0^0) and the second one I claimed from my currently d3ad grandmas house ( she had TONS or art stuff