Mostly there are 3 to 4 engine mounts on a car, did he inspect all or just one? Point is, if damage on a single mount is plenty there is a likely chance the other engine mounts may have taken a beating as well. Hence having them all inspected is critical.
Get in touch with one of the Passo parts dealer in your area. For a rough estimate my Lancer 2005 transmission mount is for 2600rs for a genuine and 1600rs for a Thailand RBI. The front (radiator) engine mount is for 1200rs RBI and the Rear (power steering) engine mount for 1500rs RBI. However, I did manage to score an all original good condition auto gear side mount and the rear engine mount RBI from the local junkyard for a single 1000rs only.