Silver Dollar is usually pretty reasonable on the price of shells. Ask for current prices of a flat of your favorite shell and I'd believe the cost would be close to most other places. A few years ago, their reloading components weren't too high either.
Uhhhh, Jake, I am pretty sure (i.e. dead certain, since I bought a couple of flats two weeks ago) that the Kemens are quite a bit higher. Perhaps they have not updated their site, at least as to shell/component prices.
Keman shells are $69.95 + 7% tax, per flat. Spoke with the counter folks and they said in the past there was a $5.00 per flat reduction for flat purchases during the big shoots. They stated they did not know if it would apply this year. Web site prices are currently not updated it appears. Hope this helps, for current info call the Gun Club for up to date info. Jake