Plenty of racers at Haydays this fall selling their race gear from last year. As much as they would like to play it off as "Rare" rare only adds value if they were a winning racer.
ie Blair Morgan's helmet from a season championship etc.
Racers get the gear, they wear it, and sell it off as their sponsors are going to help them get the latest gear this season. It's a cool piece to have and use if it's still functional. I would add no additional value to it, unless it was something you wanted to collect and display. If the racer is not recognized by the average sledder, then it is just used gear.
The only thing hand made about it may be their number badge, name or sponsor patches sewn on it. There are so many replica jackets out there now, it's tough to differentiate.
Good luck,