Upload & Sell: Off
I think the dock will be a great item to pick up used. I'd imagine that some will buy it, use it to adjust their lenses and then realize there isn't too much reason to hang on to it anymore. If I had one of the lenses the dock worked with, I'd sure as heck buy a used one to try it out and then sell it for close to the same $s.
I don't think so. That'd be like buying a pump for your bicycle tires, airing them up once and then selling the pump. No, at $60 I think it's the perfect price to hang on to. Parts wear, so future lens tweaks are imminent. Also, it can update lens firmware. Oh, and if you're shooting a sports lens, it'd be cool to quickly throw new settings onto the lens to match the shooting environment of the day.
As long as I've got a compatible lens, I'm keeping my USB dock. Based on current Buy and Sell trends, any used ones would likely be priced at or above the price of a used (refurbished) one directly from Sigma.