You can probably purchase something used cheaper than attempting to make them yourself.
I dont think you can anywhere close. I looked at used sails for my 222, the cheapest ones I found which were admittedly "worn" or needing some repair, were still over $300 each. Cheapest used main ive seen was over $400.
In contrast a $20 or $30 poly tarp, some cord, a $20 grommet tool kit, some double sided tape/adhesive, and a few hours fiddling around, and voilà! You have a sail.
And along the same lines of free sailing, or at least keeping from destroying anything expensive, all these modern boats have steel cable shrouds and stays, which offer almost ZERO give to shock loads. We read almost daily of chain plates being ripped out. For thousands of years man has used rope for that purpose, me wonders if it would be so bad to use today.