I remember the first old computer I purchased was a Sinclair ZX81 which I discovered at a ‘Trash and Treasure’ market probably around 1988. I think I paid $15 or so for the ZX81 and a power supply (no box or manuals) and the machine is still in good working order. That find started me on an “on again, off again” affair with collecting old computers that has become more of an obsession today. 
In the early days there was no eBay to buy and sell old skool computers. Instead you had to trawl through market stalls, thrift/second-hand shops, pawn brokers, classified ads and so on. Finding old computers was more about the hunt than the acquisition - you had to live in an area with plenty of good thrift stores (unfortunately for me there weren’t many around where I lived) and you had to get in quick with the classifieds in the papers. My main source in those days was a paper called the Trading Post. Each week I would get the Trading Post early on a Thursday morning and scour the computer listings for interesting looking finds. Then I would start making calls and if I was lucky I would be able to score a bargain. Due to my location I had to arrange to have the computers delivered by post or courier and payment would be by mailing a cheque. Turnaround times would be in the order of 1-2 weeks. These days I can win an eBay auction, pay via PayPal and have the items in my hands within 2-3 days. Quite an improvement!
I quite enjoyed the hunt back then - not that I actually purchased much. My PET 2001 came from the Trading Post, as did the Commodore 128D (which I foolishly sold for next to nothing years ago) and a few other odds and ends. Pickings were slim however, which made the few rare finds all the more enjoyable.
A couple of years later, 1989 or 1990, I started dialling bulletin boards and ended up running my own for a while. That is when I discovered FidoNet and the various “Echo Conferences” including a couple of “for sale” groups. These opened up a few more possibilities for finds, but still, pickings were slim. A couple more years on and I finally had access to the internet and Usenet newsgroups. This was where I really started to realise that collecting old computers was a hobby that a small group of enthusiasts were really exploring. I can remember reading posts describing how to find rare games in thrift stores, what days were best to go hunting, tricks to get cheaper prices, and lists describing the rarity of different systems and game cartridges. Many of the posters were collecting Atari 2600 systems and games and the hobby was just starting to become more popular.
Then along came eBay and things started to really take off. My first eBay purchase was in 1997 when I won an auction for a collection of 10-12 Atari 2600 cartridges. I made a couple more purchases then left the hobby for a few years. Nowdays old skool computing is a thriving scene and there is more and more equipment available to be had. Just look at the number of auctions in the vintage computing categories of eBay! Thanks to eBay, I now have a large collection containing computers that I would never have been able to find locally. I can buy a computer from a guy in the US and it will be shipped here in a week or so. I can then buy some software for that computer from a seller in the UK. Then, using the web, I can find technical details, schematics, scans of manuals and all manner of information about my new acquisitions. It has certainly made collecting a lot easier.
However, the growth in the old skool computer market has come at a cost. With more and more people getting into the hobby, prices have predictably risen. While my first ZX81 only cost me $15, today you would have to pay many times that to secure one on eBay. Then, should a newspaper or tv show do a story on collecting, people look in their attics and dust off their old computers and think they will become rich by selling off these ***ULTRA RARE*** computers on eBay and list their goods at unrealistically high starting prices. So it is starting to get harder to find good quality gear at bargain prices. Where a seller may have listed a single auction for a computer, software and manuals, these days he will list 25 auctions - one for each individual item, all starting at $19.99 (or some other outrageously high figure). With luck they will relist their auctions at lower starting prices when they fail to get any bids, but it does make it awkward to score a complete set of manuals or software especially if you have to bid against another collector.
So while eBay has helped to grow this amazing hobby, by making old systems more available to a wider audience, it has also lead to inflated prices in some areas. Still, that won’t stop me regularly checking the new listings in my favourite categories!
