I noticed the same thing when I was looking for a used vehicle.. the GMCs were cheaper all around. And as far as them being more loaded than the suburbans, that's not necessarily true... I just picked up a LTZ suburban that has every option known to man.. AC seats, dual DVDs, power front and rear seats, rear heated seats, auto wipers, moon roof, air ride, black leather, etc.. etc.. And I looked at a few escalades and yukons that did not have half those options. So I'm thinking it's a difference in certain packages that they came with.