The American Philatelic Society (a society for stamp and stamp collectors) says that while rookies begin collecting any and all stamps, expert collectors know that certain stamps are from other countries, specific regions, and for special events. Over ten thousand new stamps are issued each year worldwide, says the society. Mint condition stamps (never been used) sell the best, but used ones can still bring in the paper.
In May 2019, a collector was selling his entire collection on eBay. Opportunities for reselling are pretty good, and the investment is pretty low!
Old cell phones
You may be used to replacing your cell phone every few years, thanks to better hardware and software, and chasing after the new thing. But if you happen to have one of these huge, vintage pieces of mobile technology, take a look. If you have one from long enough ago, you could be looking to rake in the cash. Dating back to the beginnings of cell phone history.
The original mobile phone, the Motorola DynaTAC, has been seen on eBay for up to $500 – outside the packaging. Inside, think five figures.
Pins
From the Olympic Games to Sports to Disney, and almost everything else, there are zillions and zillions of pins to attach to your outfit, and some of them are worth plenty. While the Steamboat Willie pin goes for $5k, probably the most expensive pins are sports-related: the 1912 World Series Press Pin, between the New York Giants and the Boston Red Sox, goes for $57,000.
It's especially valuable to Boston fans, as it was the first year Fenway Park opened, where the Sox still play. That's a pretty penny for an old pin.
Lego trains
Do you remember what it was like to build your own toy entirely out of Lego? This was another playset that all of us can fondly remember. With these toys, you could allow your imagination to run free and create almost anything you wanted.
Take two things that people are widely passionate about (Lego + Trains), and you have one awesome toy. The Steam Cargo Trains, Diesel Freight Trains, and High-Speed City Express trains can all sell for $1,500 to $3,000. Wow!
Persian Rugs
Handwoven Persian rugs have been appreciated quite a bit over the years, although it will take a long time for that to happen. That rug your great-grandparents bought may just be worth a lot more now.
Rugs that are over 100 years old are deemed antiques, and their price is determined by size, material, condition, knot density, and design.