Collectibles are so unpredictable. With rare exception, it is very difficult to predict value. Unlike a commodity, value is not driven by Supply and Demand alone. Like the latest tech gadget or new set of sneakers, value is a function of product and perception. The difference is that in the case of an iPhone or a pair of the latest Basketball shoes, there is a history of market performance that one can look at. With individual political leaders, sporting figures or media stars, it is much more difficult to predict.
Brady himself is an interesting case. After SB LI, he was finally universally acknowledged as the GOAT. Winning his fifth and winning it in the fashion he did and then having an MVP season immediately thereafter no doubt accelerated his value to Collectors.
Some would argue that his Collectible value would have hit a peak the moment he became MVP this season, on top of last year's win.
What happens next? Who knows? If he doesn't win another SB, his value could flatten or even dip until he is formally admitted to Canton, when his market will heat up again.
If I were your dad, who seems to have a fact-based opinion that he has something of value, I'd go to a couple Boston Area memorabilia dealers and get an estimate.
Then he has to make a decision around how he feels about the future value of what he has. That's where the risk comes in.
He could then either put it up for auction or he could consign it to a dealer, in which case he would agree with the dealer on the price he will take and the commission to be paid. If the dealer gets a lower offer, he would have to call your dad and get his agreement. If you're talking anything more than a couple thousand dollars, he'd have to fax or email him permission to sell it for less.
