I've gotten the 3 plus 1 free at Pep Boys, for their brand AT tire (Definity?) in a 30x9.50-15 that I ran on a '98 GMC Sonoma with a 2" body lift (youngest daughter now drives it). Also got the 3+1 deal from Firestone on their Destination AT, 31x10.50-15, for a Jeep Comanche truck I used to have. Both tires were a good deal at the time, MUCH less expensive than a BFG AT. I'm running Sumitomo ATs on my Monty (265/70 on 16x7 Tacoma steelies), and they don't stick out at all, give a good quiet ride, and perform well in the snow and slush. I was in Wally World last week, and couldn't believe how much tires have gone up in price. They carry a Goodyear Liberator AT that looks to be an awesome tire, but they want about $185 for a 31x10.50-15, plus mounting, balancing, valve stem, and tire disposal (add another $15).

If you have a Treadquarters / Merchant's Tire / Kramer Tire / Firestone / Pep Boys near you, I'd check 'em out for prices. 'Course you could also look on Craig's List, which is where I found my Tacoma steelies.