Um... that's really weird. Xero: First, I suggest you hang around here. No, really. Browse past topics of this forum, and you'll get a good idea what standard dev equipment costs, what consists of a full kit, and even if people are trying to sell any. Ask questions if you're confused - there are plenty of very knowledgeable people here more than willing to help out. Keep an eye on the marketplace, as interesting and rare things (not JUST dev-related) go up fairly often. Beyond that, just have patience - things turn up occasionally on eBay or make their way over here. Above all, keep your nose clean and have fun.
You should ask yourself why you want to collect them. Is it for strictly collecting purposes? Or do you actually want to develop games on them? Becasue if you just want to play games it's really not worth it. If you want to develop games keep in mind these aren't the kind of machines you can just call the company up and get tech support. Chances are the fact that you own it is illegal. Be prepared to search high and low not just for hardware, but also software, support docs, etc. And be prepared to spend a lot of money.
*Insert inapropriate joke here* Lol. That being said, if you're looking for dev kits to program for then you should probably look towards a GBA flash cart. If you're just looking to collect cool stuff, i'd recomend starting with a PS1 debug station. They're a cool color blue and they're pretty cheep (I'm sure assembler could help you out there). You can pickup protos and review disks for around $10-30. If you're looking for something specific, once you've gotten to know the place and posted a few times, feel free to put out a request in the marketplace. If you have questions on specific hardware, there are guru's here for every system you can imagine, from Atari to Wowow (or however that's spelled). Some of the stuff we talk about is really expensive, but most can be had for reasonible sums. Cheers. (i've always wanted to say that)
or ask your old man to buy couple of game studio or publishing company or two... unfortunately mine went off and dealt with government/army corp before retired...
Im just into systems, not really DEV or anything like that, but i bet this guy is, so just search, theres 115,600 posts, so that helps
Hawanja also makes a good point: dev systems, while cool to collect, often sell for such amounts that (unless you're, like, super rich), you're probably not to pay to have just sitting on your shelf. But that aside, there's a world of infinite rarity to be found in collecting just 'standard' consoles and accessories. The Dreamcast has about a billion and a half 'limited edition' systems, and the Gamecube is pushing that number as well.