In Dec I sold our 5vr and 2005 2500HD, 8/1, Ally, ext cat, 4.10, shortbed. It was a perfect combo for us.
Trailer loaded was 9200-9300 lbs and the truck towed it with power to spare. Merging onto freeways, climbing steep grade was no issues whatsoever.
Wit the 4.10, o/d kicked in around 58-59 mph, which was perfect for CA towing speed limits. We averaged 9.3 mpg on all of our towing, but you have to drive with a light foot.
Hated to sell the rig, but we had not been using it more than a week or two last couple yrs. Sold it to our BFF and they have already made 6 trick to Pismo Beach and one to Las Vegas - and they love it.
I also agree the price is a little high, you should be able to get it lowered some, not much tho.