What would cause a "lopsided" Suburban?

I am looking into a 1999 Suburban. This is a one-owner vehicle and the owner is under the impression it may need shocks on p side. The vehicle is about 2" lower on the penger side...?? What is up with that? Is it probably minor like air in tires, a shocl or two.... or could it be major? It drives fine, can't tell at all. Clean title, clean Carfax,original title, have all service records... hhmmmm.