Holy cow that is one BIG tent, are you nuts? (no offense), site says its at least a 6 person tent ! (or do you the 10 person one)
I think someone tricked you, there are a number of qualty, easy to set up tents that are much smaller than 73 pounds and you and you son would still have room. (And just as much fun) We backpacked for a week carrying less than 73 lbs !
This link has good basic thoughts on tents
Camping Basics - What Kind of Tent - Choosing a Tent to Meet the Occasion