Get Out! I'm also looking to update my 1995 E36 interior. According to www.Leatherseats.com
you could do it yourself. They sell the E36 leather seat sets for the entire interior (seats and door panels) for around $750 + $25 to ship. Everything is pre cut and all you gotta do is remove your seats and current seat skins and wrap, then staple (w/ hog rings) the new leather skin on. You also gotta glue certain parts on like the door panels and viola after 4-6 hours you got a new interior.
Actually someone told me its NOT that easy to DIY. And most places around the NYC area are asking for $250 and up to do the seats, more for the door panels.