Most things are admittedly easier when you have the proper tools and a solid workshop to begin tackling things in. It also doesn't hurt to have a couple of like-minded buddies who are willing to delve into the wonders and/or horrors that lurk beneath that Facebook Marketplace purchase you just plunked down your hard-earned money on.
But at $300 for a trio of little late-70s Honda dirt bikes, it's difficult not to see why this purchase seemed like a good idea. Maybe not for me (I don't have the room, sorry), and maybe not for you either. Still, if you have the room, tools, and inclination to see if you can make one or maybe even two good-running bikes out of the set, that works out to around $150 apiece, give or take whatever consumables and/or parts you add into the equation from your own personal stash.
