Perhaps my initial post was not clear enough. I was not advocating doing this and I am well aware of normal lights on / off procedures. Also I am well aware of the problems of extra loading during start. It was in conversation with an aircraft engineer who was talking about how much better the life was when they were wing-mounted. He opinioned keeping lights on for shut down may improve the life. (Actually no mention of start, I simply put that in because that is presumably going to cause the same problem; then again perhaps not, maybe it is when the filliments are still hot, but not on, that it is most vunerable.) I wouldn't consider making every start with lights on, especially in a work horse with frequent start up and shut down cycles. My reason for the post was to gather opinions on the technialities of the best way to improve the bulb life. As a professional pilot I try to take critiscism constructively but I wasn't expected to be flamed on airmanship issues over this!
P.S. On the subject of non-aviation parts being often better and a lot cheaper (lets leave the legality issues alone here) I know of one ex Islander operator who when he needed to replace the bushes in the electric flap motor, found that the replacement bushes for a high quality food mixer where identical at a fraction of the cost!