A IIci, while a fantastic machine, isn't particularly collectable. You might be able to find someone willing to pay a couple of bucks for one, but $100 is a long shot.
I am an Apple/Mac collector, I watch eBay's Vintage Apple section all the time. The IIci is not a very desirable unit, I rarely see them sell. You might be able to sell it for $10.00 if you are lucky. They are ugly, bulky, very slow, and not rare at all. They were not a Powerhouse when they came out (The Mac II and IIfx are more collectible). I see IIfx machines go in the range of $200 - $400!!! IIci Macs are not popular at all. They are very hard to sell.
I like the IIci - when it came out it was quite the machine. Fast, smaller and better designed than the II, and 32-bit clean. Apple sold a ton of them, but that's also why there's a lot of them out there.
These days, there aren't a lot of 68K machines that are genuinely collectable - at least in the sense that they're worth enough money for most people to concern themselves with. I think the only 68K Mac that I'd bother doing anything other than giving away free would be my Macintosh TV. Just last month, I passed on a lot of six IIfx's. I think they ended up in the dumpster.
^^^ in this case it was a University lab getting rid of computers. Recyclers, government auctions, and schools are a good source of free vintage equipment, but you have to be patient. I wouldn't purchase from eBay unless looking for something genuinely collectable, like WardC's sweet PowerBook 170.
Ouch, sad to hear that those machines got dumped! I check craigslist every now and again to see if someone is getting rid of a machine. I got my Macintosh IIci for free, someone on craigslist was giving it away and since I was buying a box of his System 7 install he didn't mind meeting half way. Since my Dad's first machine was a Macintosh IIcx I figured it wouldn't be bad to keep the IIci for the Power Supply alone.
It depends very much on condition and completeness. A "perfect" as-purchased IIci with original packaging might bring $100 from a serious Apple collector. Other than that, I doubt you could get much more than around $25 for a working machine with honest wear & tear, even from a "collector". Most vintage computers, even Macs, are not very valuable.
I once had a bit of a vintage computer collection, back when I started my undergraduate years...my only remaining Mac II is a IIci. It's a great little machine, and while I don;t want to sell it, I consider it nearly worthless from a monetary standpoint.
My IIci doesn't have any of its original part - mitsubishi floppy drive instead of sony(not auto-inject) a 9GB IBM HD, 4mb simms X4, 4 1mb simms, i added a fan on 5v and changed every capacitors. But at least i have the cache card, a 824 gc and an ethernet card. So i think it wouldn't cost more than 30$