I have been having needing sawhorses lately, and only have 2 has gotten me thru sofar, but sometimes I need 4 and start using my wife’s kitchen chairs. This maybe a good alternative with some scrape wood and old hinges from doors (another thing is the sawhorses for me need to beable to fold up) instead of buying some more. However it looks like the author “bought” all the material to make these. I think I would just have gone to harbor frieght and bought some cheap ones instead ($10). I think the materials to build these would run me around $20 at least.
http://www.instructables.com/id/Making-Simple-Folding-Sawhorses