I buy rust pitted and worn examples if it is a wrench I know will never get used. It only has to represent the type or variation.
While my collection has no farm wrenches other than one Planet Jr. I do have a selection of early mechanic's and car kit tools as I can.
What you gents collect must have higher resale value in the market than mine somehow, I get them cheap and can barely give them away at resale here.