I seldom use display plates because they are expensive. I can get them custom-made for me not far from where I live, in a small shop which does plate engraving in plastic or metal and also works on keys, locks and stuff like that. They calculate the price basing on the surface of the plate plus the number of characters to engrave. So a nice brass plate with say 30 characters on it would cost 20-30$. So I do it only when I need something special.
Happy modelling and have a nice day
Pawel