Not sure if the sidewall comment was in reference to the 739 or the Michelin.
It's certainly true of the 739, but that's where the weight comes from. Anyway, IMO, a tire with a stiff wall at 8 psi and a tire with a lighter wall at 12 aren't that much different to me, but I can feel the way the weight changes the handling a great deal more. The 739AT is about 2 pounds heavier than the MX51, and the 51 bites a lot harder.
Retail pricing is one thing. The prices we actually end up paying for Dunlops vs. Michelins is another.