Tread depot had them for $298 a tire, but then I would have had to find separate installation and warranty. Most local places had to special order this size in. Some local shops couldn't even find them from their distributorships. Another popular tire store wanted $1771 for tires/warranty/rotations etc. I went to Les Schwab and they had the size in stock and had them mounted in an hour or so. $1500 out the door with warranty, rotation and the like. Still steap, but when I need something I hate to wait...
This site was helpful in determining tire size changes and what effects they may have on the truck etc...
https://tiresize.com/comparison/