I strongly advise against paying a premium price, and here's why.
Seeing the stars in person is what happens outside, on the red carpet. Anyone can stand there and see them, ticketed or not. In some ways, by standing at the red carpet (and hence delaying your entry into the theater), you won't end up with very good seats. You might have a chance of a longer Q and A at Black Swan because it's the last film at Roy Thomson that night, but no guarantee.
Also, it's been my experience after 5 years of TIFF-going, that you can get almost any ticket on the day of the screening at 7 a.m., either online or by phone. The galas in some ways are easier to get at the last minute than other screenings because they are in venues with many seats and because many filmgoers are put off by the high price.
Back in 2005, for instance, I wanted to attend the premiere of Pride and Prejudice, but the first day of sales, it was sold out. When I picked up my other tickets, the TIFF person told me to try again on the day of the premiere, and sure enough, I was able to get 4 tickets.
All tickets that are sold out today will continue to be listed as sold out until the day of the screening. The single film I could NOT get last year on the day of the screening was An Education, which was in a very small venue (one of the AMC rooms).