Well, first off, this is your friend. I would let him know about the true value of the gun. He's your friend. I would think that you owe him that. Then let him make a decision. Maybe you could negotiate a deal for both of you. You will be getting a very nice (and desirable) revolver. Perhaps at a good price. This is a golden rule matter in my opinion. Unfortunately, it is what it is..... $200 is a great price. Would we all have a friend with one of ANY great old Smith revolver.....at a good price. It isn't like going into a store with one of these in the shelf. Most of us would break a finger or our hand getting our wallet out....! But.... If it were me, I'd tell him that he has a great revolver and you want it but negotiate the price. Or at least let him set a price after better info as to value.
Holsters: I've always liked Tex Shoemaker for holsters. Lots of good holsters on this forum for sale (good used ones). Bianchi is still making holsters but I am not sure that the quality is as good as when himself was running the business in Temecula. Many current manufacturers advertise here also. Barranti is a great maker, located in Pittsburgh. I have one of his and the quality is fabulous. Good luck. I hope that you get that revolver.
Qualification: Not meaning to imply that you haven't already thought this out. Making my statements in re: your request for comment. In any case, I guess that you will be discussing the price with him. Hoping that you do well on price for this and your pal gets a price that he can live with.