I think what we're seeing is that the true collectors are looking for pretty in a box with a manual. Adding a green MIT to the collection makes it worth the price if you want all the versions. So, where are all the Rocktek and Rockson collectors?
I guess they have to be GOOD pedals to be collectable....
The prices on the SP-1 do seem to vary quite a bit still... Check out the latest auction on Ebay: 7374872824 That silver screw SP-1 went for $300, with only three bids. Quite a bargain compared to the other auctions recently...