If I were really wanting to gamble, I'd hold my bid at the wholesale price of 20 MS63 1938-D Buffs, or about 200 bucks. This is based on the end coins being MS63. Adjust accordingly based on your grade. The people bidding over $350 on this thing right now are gamblers, dreamers, ignorant, or some combination of all three.
Collecting/saving BU rolls wasn't really a "thing" prior to the mid-late 1930s, and a ton of BU 1938-D rolls were put aside by collectors in anticipation of the new
Jefferson nickel due to be released that year.
I am almost certain this is a modern roll using a vintage wrapper. Not only does the roll display no signs of handling, staining, wear, or contact, the end coins are untoned, which is exceptionally unlikely of for vintage shorty BU Buffalo rolls. In addition, how would the seller know it was a solid date/solid mintmark roll without having either opened it or rolled it themselves?
Vintage wrappers from a variety of makers, mints, and banks are available all over
ebay in quantity for cheap. There is also a good probability that the nicest coins will be the two end coins, and the middle will likely be filled with off-quality pieces, lower MS grades, etc. There is a great deal of profit to be made in selling modern put-together Unc rolls using vintage wrappers (look at the bidders gobbling up those "CC"
Morgan dollar rolls for 3-5x the price of 20 MS63 1883-CC/1884-CC Morgans!)
There are real vintage rolls out there as opposed to the rolls made by sellers using vintage wrappers, but they are much less common and usually come in the form of hoards or estate purchases.