As said, these aren't exactly high end bikes, but don't let that stop you, it doesn't stop me. What you need are parts bikes. How do you get them? Honestly, just ask. In the spring I just put in a request in the "Items Wanted" section of my local town facebook group or CL/Kijiji that I want dump/trash/scrap bikes...that you're going to reuse parts, etc. After that seems to dry up I say I'll pay $5 for anything that's whole...that usually brings a flood of them in, plus free bikes that people just want to give you.

Now, you're gonna have a crapload of worthless, cheap ass department store bikes...but these bikes usually have at least a good tube or good tires, for sure good cranks, many have good pedals, shifters, derailleurs, cables, you name it. I rarely keep a frame unless its a bike I really like or in nice shape, and just dump the rest (look up some of the stuff you can build with bike parts BTW, you will pretty much just dump the bare frame). You will of course get bikes that are 100% bike shaped trash, but I find that about 10% of the free bikes I get are actually something pretty cool or valuable...that's 1 in 10, so you need volume for sure.

So, for a bit of collecting time and tear apart time (people will bring bikes to you, but I usually offer to get them), you now have lots of free, functional spare parts and you can pretty much rebuild any bike that comes your way including your own fleet, which will now also have any amount of accessories from left over gel seats, cargo racks, etc. Where I live, you can get $40 for a functional bike regardless of brand and low end bikes are can pretty easy to adjust especially when they are just friction shifters and such. It's old school stuff, but sometimes people just want a bike that goes from point A to B at their camp 1 week a year...and that's the price and bike they need. You'll learn how to work on bikes and you'll have nothing but hobby time spent into it...and sell one or two and you can go out to eat.

There are lots of tips and tricks, but most people start out on low bikes, as they get more successful and make more money at is, the move up in bike scale and style, but a lot of people start at the bottom and work up, adding cool stuff they run across as they see more and more bikes. Good luck!