Hitcha
a partial set is fairly common but a full set is quite rare.
I would counsel patience as anyone with a full set is probably collecting it. When he decides to liquidate his collection, which happens to us geekhackers from time to time when someone needs to buy a house or has some medical emergency, you'll get your chance.
I believe SpamRay was like buying a new (or old) keyboard every other day until he needed to buy a new house. I'm still sniggering about it, heh. He actually told me no, his new house is not to store his keyboards in, but I know better. When he gets more floor space he'll be back in the buying business.
)
In the meantime you can wait for SpamRay's moving house sale. Even if he doesn't have an MKC set for sale, you can bet he has a ton of things to sell that he can't remember buying.