If it’s a restored example..check with people dealing in the product. Restoration is not cheap or easy - but also more a labor of love more so than profit.
Poor condition, unrestored - value is low - but you will always find buyers. Some people like projects and always find buyers.
Deere is of course the “icon” brand. It will always sell better than say an Allis Chalmers or older red belly Ford. In terms of collecting- it’s Deere, International Harvester, Ford then the rest in popularity.
Unrestored example - varies greatly by model...but ballpark puts you at 1k - 3500-4K in general. Expecting new tractor prices because something is old and green is likely a dream...likewise if someone tells you it’s worth scrap - know there is a market for solid parts donors.
Try googling old tractor parts yards and callling...or check out Farm and Dairy...some resellers advertise in classifieds there.