Here's a very simple build for an extremely affordable book charkha. The main purchase was 2 wooden boxes (around 7.00 each). Not a lot of parts to purchase or carpentry needed. This was constructed using the lids of 2 wooden boxes, Jenga blocks, cardboard, string, a sewing machine bobbin, pieces of wooden chop stick, adhesive velcro and an empty pen barrel. Everything is held together with Gorilla glue. The only purchase in this build, for me, were the boxes. We've had the Jenga game for years but was missing some pieces to I relgated the blocks to my craft bin. They've come in handy for a lot of projects. I already had the rest of the materials in the house from other projects.
The drive wheels were made in traditional charhkha wheel fashion by making slits in the cardboard and criss-crossing string from one side to the other. If you cover the cardboard with some wood grain Contact Paper, or even decopage, it will look a lot prettier.
The spindle is made from a double ended knitting needle with a plastic sewing machine bobbin. I heated one tip of the needle and poked it through the bobbin for a perfect fit.