I've pretty much finished my world's cheapest scrap salvage build. It's an old Townsend Shaniko. I set myself the brief I couldn't buy anything over a tenner for it and wherever possible I had to recycle original parts of the bike or use stuff I already had stashed. Apologies for blurry pic, phone's a bit knackered...
Rear freewheel (not even cassette!) stripped out for single speed use...
Cheapy Townsend crankset repurposed by chiselling off outer and inner pressed rings, revealing one flat steel ring perfect for lining up/ratio...
It's still surprisingly heavy but rides really comfy, weirdly a little bit like an old beach cruiser feel. I bloody love it.