Go to a big truck tire shop. I've found the best prices there. True, the truck tires ride a little harder but that's because they generally are 1-2 load ranges higher than those sold for RVs. They are almost always marked "regroovable", too. For us, that doesn't really matter as we generally "age out" our tires before the tread is gone but I feel better that there is more rubber between what ever I run over and the inside of the tire. One thing I have noticed is that truck tires are always marked for 120 max PSI and the truck shops always set them to that. When you get home just lower it to what is on your RV's tire label or it will ride like a Flintstone car. I find there is a lot more tread left on the truck tire once I hit the 7 year mark and go shopping again. The first time I did this the tire guy had me lift up the Michelin I was replacing and the truck tire I was buying. Truck tire was MUCH heavier. I liked that. Truck tire shop prices are usually about $1000 less than the prices above. I like that, too.