It sounds like a reasonable price to me. That seems like a fair amount of work, by trained gunsmiths no less, for that ammount of money. I assume that is factory warranted as well. You might find it cheaper locally, but work by the guys who built it is probably going to be pretty good. I don't know what shop rates are for the average gunsmith, but $250 might be 3 hrs labor on your car, probably less most of the time.
If I had a pretty polished finish I would probably pass on the bead blast, but that's me. The real question is: What problem, if any, is it fixing? Glare reduction maybe? If there is a practical reason to do it, then you have to decide if it applies to your application.