WELL, it sure gets hard to best-guess the line between buying cheaper - but properly sized and rated - off brands, and going for the top of the line stuff.
They all seem to have the same age constraints, so IF the cheaper stuff simply wears out a bit faster, a guy like me that puts relatively few miles per year on RV tires MIGHT be foolish paying extra simply for a name brand that still is supposed to be replaced in 5 years or so.
I've found some properly sized Ebay no-name tires that are the proper size and F rating as the 8R 19.5's on our '88 Winnie, for $178 each, delivered - as long as they carry a USA DOT stamp, and are dated as being well under a year old (as the seller/tire distributor claims), why should I pay $150 more per tire only for the name on the sidewall?
I've seen far more Goodyear, Firestone and similar brand name tires blow out shortly after installing them than the Carlisle's on my 5er and boat trailer.
NO, you don't ALWAYS "get what you pay for"!
And simply forking out lots of extra $$$ just for a warm and fuzzy feeling simply don't cut it!