Question about contracts (and the Campanella contract in REA auction)

[Topnotchsy]

I've learned a ton on the site, and was hoping someone can help educate me on this. I've been increasingly interested in contracts, but still find I am a real amateur.

One of the items I was bidding on in last night's action was the the 1956 Roy Campanella contract.

In researching Campanella's contracts I looked at older sales:
1950 Contract - $33,000 - 2017 - REA
https://www.robertedwardauctions.com...st-mvp-season/

1958 Contract - $32,588 - 2014 - REA
https://www.robertedwardauctions.com...al-his-career/

Based on this I had assumed that the price would be close there. I was surprised therefore that the price ended for around $5,000 and was trying to understand why this was the case.

Does it have something to do with the specific item? Would it possibly be connected to the specific season (1956 was a down year). Was it related to the item itself? (I noticed that the rest of the info is not filled out and wondered whether there are differences in which copy of the contract it was.) Was it just random?

1951 Contract - $5100 - 2018 - REA
https://bid.robertedwardauctions.com...e?itemid=53158

I'd appreciate any insight!