Here’s a phone call I recieve at least once a summer:

“Hi, Derek: I’m at this rummage sale, and they’ve got this computer thing, I think it’s a video game…The guy has ‘make an offer’ on it, and says they’re collectible. What do you think it is worth?”

Collectors of all sorts tend to hate these calls. Expertise in any field will lead to tough-to-answer questions: “It says ‘California’ on the bottom,” isn’t necessarily enough to identify a $500 pottery piece from a $5 one, and neither is the maker enough to identify the value of a computer. Adding to the confusion are people who think, just because it’s old or because someone mentioned one on TV, that it deserves a $50 pricetag. Still, I’ve gotten pretty good at getting close. No collector wants to buy something for $50, then find them for $5 on eBay, and collectible dealers don’t want to lose money on buying an expensive machine that has no resale value. Here’s my methodology for evaluating computers, both for collecting or for reselling:

1. Does it have extras with it? Whether a video game or a computer, you want to make sure it’s well accessorized. The TV videogames invariably have controllers, a plug-in, and a cord to connect it to a TV. A computer should have a keyboard, mouse, and monitor, possibly a printer, scanner, modem, or other useful parts. The more parts, the more likely the machine will have everything available to make it usable.
2. Are there games/software? Modern computers don’t necessarily need to have disks along in order to test it, but it’s essential that a video console have at least one game. If the computer seems to have panels missing, exposing empty internal spaces, it may not have any software left.
3. Complete game consoles almost always have a buyer. Video gamers aren’t always looking for rarity: they simply want to play games. Nintendos and Segas, which were manufactured by the millions for a number of years, can often be bought at a rummage sale for a few dollars, and on the a collector may pay $10-$20 for it. A well-tested machine, with good controllers and everything to start playing immediately, will go higher. Due to the large number available, however, don’t expect to make hundreds off it. This even goes for older consoles like the Atari 2600 — so many exist that there’s not a rarity demand, so prices tend to stay low.
4. If it’s pre-1990s, and you don’t remember seeing a commercial for it, it’s probably valuable. Even bigger manufacturers, like Atari and Commodore, made computers and gaming systems that fell flat, didn’t sell well, and were quickly discontinued. If you’re surprised by an odd PC with the Atari logos all over, or a strange little computer with the Commodore logo on it, someone’s probably looking for it to complete their collection.
5. PCs have little to no value. This one is a little tough to gauge, because pre-1990s Amigas, Commodores, and Ataris can be quite valuable, while the Macs and PCs only have minimal value to tinkerers and repair shops for parts. The IBM-compatibles are the worst, because most are assembled from off-the-shelf parts and have no inherent rarity. 1985-1990 is a nebulous time for computers, when standardization of hardware was occuring, so fewer of the unique machines were being made. Collectors prefer machines made by individual manufacturers from original parts, not ‘clone’ machines from various makers.
6. Apples and “Classic Macs” have moderate value. Any pre-Mac Apple computer has collectible value, and the early all-in-one “Classic Macs” have a following. All fit into the nostalgia-collecting realm, where many adults today had one of these computers either at home or in school. The later the model, the less rare it is, but $20 for a “Classic Mac” isn’t an unreasonable appraisal, and older Apples (in working condition, with accessories) can be worth $100 or more.
7. $20 is the most to spend on an untested complete machine; $5 for an incomplete machine. Untested complete systems still have valuable components: power supplies, controllers, disk drives, software. Fragmented systems, such as one missing a controller or power supply, still have moderate value to people willing to take a risk on an untested piece just to get their system back up and running. If it’s a common machine, like a Nintendo or Classic Mac, you can’t expect it to be worth more than $20 in complete working condition, so no matter how clean or in nice shape it is an untested machine is still untested.
8. Anyone asking more than $10 at a rummage sale better have a good explanation why. If not, they really don’t know what it is, and cannot reliably tell you if the thing even works. The best question to ask is, “does this thing work?” with a confused look on your face. Really, it’s the best way to get an honest answer: someone in-the-know will have a long description of what the machine is and does, and a shrug or an “I don’t know” isn’t good enough.

#7 is probably the most important of the guidelines. If you’re interested enough in an old computer or video game console to consider its value, it must mean you want to play with it for a little while (don’t deny it!), and $10 is definitely cheap enough for an afternoon of entertainment. Following the rest of the rules will ensure it’s useable and entertainingly unique, and you’ll be less likely to be disappointed. Once you’ve gotten your Commodore or Atari, you can start watching rummage sales for new games, other accessories, or just know a little more about the systems next time you run across them. Vintage computers can be a lot of fun for tech-minded collectors; just make sure you don’t waste your money, and try not to call me every time you see something with cords attached to it.