I have a set. Needs floats (previous owner actually drilled holes in them), Orings between carbs, plugs and gsxr400's rebuild kit. Probably $200 of parts that look like they should cost $10.
Anyway it is $100. And then you have to put it together.
I bought it for $80 on Ebay and cleaned the crap out of it, only to find that it leaked gas and needed a lot of TLC.
I was keeping it to play with as my 1992 400 has a common 4K dead spot, and I wanted to have 2 carbs to switch between for testing. As it turned out, I just rev the crap out of the bike and try to ignore the dead spot.