Buy low on Craigslist, sell high on Amazon
Craigslist — Buy freaking everything dude. I stick to the Computer, Computer Parts, and Electronics sections mostly. But one hidden gem on Craigslist is the Free section. You would not believe the stuff people will give away on there. Back in the day I remember getting a brand new in factory sealed box (NIB as they call it) SuperMicro server! YES, THIS SERVER WAS FREE!
Recently I was able to acquire two Dell 3110cn color laser printers for free, a software developer was re-modeling the office and had no use for them anymore. These were in amazing condition, had 5 toner cartridges in each (Yes these are $$.)
He also threw in a brand new toner cartridge, albeit re-manufactured, and a presentation easel/tripod. Each printer would sell for $200, 10 used toners for $40-$60, new toner for $60, and the easel for $20. Amazing. Now it’s not easy to get this, there are a few tricks to getting these. First, you HAVE to be the first person to respond to the posting, if it’s been an hour, you’re out of luck.
Second, you have to be able to pick up ASAP, or whenever the poster has requested, otherwise you could risk losing out on the opportunity because the poster will just move on to one of the 50 other people who responded to the ad. Third, it is more likely to find high-end items in high-class areas. Here in Orange County, California, you’re not likely to find much in Santa Ana, but in Fullerton or south county like Irvine or Mission Viejo, they really don’t care about the money. They just want to get rid of stuff.