I can't remember if the price they advertise includes the digging of the hole. There is also the question of whether there is easy access to your property for the truck to deliver, if a crane will be required to off-load or to lift over the house, if the ground is easy to dig out - ie if there is rock and they require extra work, and if there are any sewer pipes / electrical lines that run through your yard.
Sorry, I would have to talk to dad to get a more definite answer for you, but I hope that helps a little