Fear, there is a method to flipping mastery on craigslist. It takes a while to really get good at it, and to decide whether it's upgrading to better things or money that you're after.
A lifelong buddy of mine is the best I have ever seen at it. A couple of years ago, he found a silver quarter in his yard when he was digging a hole for his mailbox. I told him the coin itself wasn't worth a ton, but the book value on it was $45. He put it on craigslist in the barter section asking for trades. A guy told him he was trying to collect every year and mintmark for those quarters and offered him an old rod and reel that was in his garage when he bought his house that he didn't want. Since my buddy loves to fish, he made the trade and used it a few times.
He showed the rod and reel to my dad who is a huge fishing nut, and he said it was some kind of vintage rod they haven't made since the late 70s and he could probably get a few hundred for it, so he put that up for barter and got offered a non running 4 seat filthy golf cart.
He got the golf cart and found out it wasn't running because the ignition wire was broke. So he spliced it, cleaned up the cart, and drove it around for a few weeks and decided to put that up for barter.
After a few weeks on craigslist, a guy offered him an old beat to hell Bronco. Since it was beat to ****, the value was actually lower than the golf cart. But my buddy is an autobody repair tech, so he had plenty of supplies already at his house, and made the trade and fixed it up nice as hell and it's one of the sweetest Broncos I've seen.
And to this day, he can honestly tell people that he got his sweet as Bronco for a quarter