Imagineering covers everything from engineers to architects to the art department to design staff and lots more. There are different salary ranges for each of those roles so it is impossible to give one answer.
DH is an engineer for a large company (not Disney). Just within his section the engineers make vastly different salaries. Experience, job performance, years at the company and lots of other factors play into what they make. I am sure it is no different at Disney.
Disney has a history of paying on the low side. Their reputation and the sheer number of applicants for any position allows them to pay a bit less than the average.