I bought a 26' Haulmark Elite II for the same kind of money. The box was 26' x 8''-6" (102"). Some makers sell length from the ball to the rear of the unit. It was built 16" O. C. everywhere, floors, walls, ceiling. Many others have some 24" O. C. spacing, even in the floors. I didn't have any water leaks at all.
I suppose the one you asked about is a tandem axle trailer and the GVWR is 10,000 lbs, and not a GVWR of 5,200 lbs. I made sure I got the 10,000 rated trailer instead of a 7,700 lb tandem axle trailer. Cannot comment on the model you are considering.
Wells Cargo has improved their line of trailers but they are still more money than I want to spend. They now include LED lighting but still use 24" OC floors. Featherlight was built close to my last home. They make all aluminum and some steel framed trailers. None of them come with any type of plywood lining to protect and prevent items from punching the walls from inside. An aluminum floor is VERY slippery when wet, Featherlight units.