Tractor Data will tend to give an idea but keeps you guessing as to if things such as wide front end axles and hydraulics are included. I would ballpark a last year A with roll-a-matic axle, hydraulics, gas engine at 2,250 list price. Deduct 250 dollars for a B with same features making it 2,000 dollars. G all fuel, roll-a-matic axle at 2,450. 3 bottom trailer plow model 55 most likely 350 dollars. FB 15 X 7 drill 500 dollars. 227 corn picker most likely 2,750 dollars. Again, all guesses based on Tractor Data. Some guys have JD price lists and I saw one on eBay a year or two ago for a very early 1950's JD equipment price book. I've got the books for 1971, 1992, and 2002. I would love to find one for mid-1980s, 1980, 1966, 1963, 1959 to mention a few. Went to a show in 2019 where a vendor had a very nice 1977 and even let look through it briefly. Maybe you will get lucky and somebody has a 1952 book that they can quote down to the penny in terms of price.
It should also be noted that JD as well as other equipment companies offered hefty discounts on last year equipment to clear inventory for the new products soon to be released.