I think it's pretty typical of a school's bowl game allotment. Purdue's initial allotment for the Music City Bowl last year (and Nashville is less than a six hour drive from W. Lafayette, although it must have seemed a heckuva lot longer than that driving home - lol) was 8,000 and Kentucky's Citrus Bowl allotment was 9,000.
Remember, too, that the official allotment is just a portion of the tickets sold to the fan base. Many people buy/bought directly through Ticketmaster or the secondary market like StubHub. Also, and as noted above, the bowl president commented that IU has sold more tickets for the Gator than any other Big Ten school (other than Penn State) in recent years. We're definitely going to have a big crowd of Hoosier fans.