I'm looking to get a new lens that's a wide angle (i.e. ~10-24) that's less than $800 (under $500 ideally). I'm going camping in Newfoundland and Labrador for two weeks, and want to pick up something nice for landscape. I don't have any brand loyalty, so I don't care if it's Tokina, Nikon, or whatever, as long as it gets nice photos and isn't ridiculously expensive.Thanks!

The Sigma 10-20 (2 versions available) meets your needs--I had one and it is very good.  The Sigma 8-16mm is better, but will exceed $500, unless you get a good used deal.  The 12-24 Tokina, first copy is selling used in the $300 range and is very sharp.  BestJT