Most online quotes for Maxxis 235 80R16 LRE tires that I found are about $700 delivered. Add $100 for mounting/balancing and it comes up to roughly $800 from a "discount internet dealer" so I'd say the 12% or so extra you paid (add sales tax and it's less than 12%) isn't that far off from the "cheap places".
At this point, you've got the tires, your RV is rolling again, it would have cost more to order them from a cheaper place and pay for 2 or 3 nights at a campground while waiting for them to arrive. I wouldn't worry about whether you saved a little, the important thing is you're back on the road without damage