Definitely a cross on the top one, but not sure whether it's silkie or polish cross. The light pink skin makes me think Polish. Does it have feathers on its feet? Not even positive the bottom one is a silkie mix at all, either.
Can't see the white one very well, can you get closer pictures and make them bigger? The second one I would think maybe a RIR with Silkie. I can't see a lot with the head/comb, but does look like a walnut comb and purplish?
The white ones seem to be one silky cross and one polish cross. The one in the back seems to have dark skin while the other looks way to light in skin color to be silky, but who knows. The tops seems to small to be polish... maybe a silky crossed with polish and something else?
The second one, a little dark to tell much, but seems to be a silky/RIR cross.
I usually wont buy anything from auctions and farmer's markets... most people are just trying to get rid of their mistakes and unwanted birds and have no problem in wanting to fool the unsuspecting buyer into buying something that is completely NOT what they say it is.