Recently the prices have been all over the board on ebay. The middle seat sold for $750, $600, $450 and a set sold for around $1200, $1800 and $2100. There was a reproduction set of 1941/47 seats that did not sell at $700.
I linked up plummer with a front seat and middle seat last year for I think $150 on one that I found on craigslist.
I just found a fairly complete Suburban with the middle seat in Dallas Texas on craigslist that I purchased and a friend stripped for me. It was really cheap considering what I got off of the Suburban.
And from what I can see on ebay, it's been a crap shoot on prices lately. About 6 months ago a complete set of 12 restored and polished fender trims sold for $1200 and $1350 and in the last week a set of 5 decent pieces and a set of nine dented pieces sold for $385 and $965.
So what I am saying is the market price depends on whose looking at that moment they are for sale and it could range widely.
Do you have a seat available or are you looking at one that's available? What kind of price do you have in mind?