So long as you aren't scraping the lid against asphalt, the plastic lid is probably fine. Unfortunately, most homes don't come with stamping tools and dies appropriate for making jar lids. Probably the cheapest form lid I could imagine is oiling up the jar thread, placing a cheap dish cloth over the thread tight, and then soaking it in wood glue, then cutting off the excess cloth. Would not survive a trip in the dishwasher, and you'd probably want to have some sort of resin finish.

Actually, I guess you could stamp a few layers of aluminium foil maybe