Yikes! Not cheap at all. And that's for black painted, not chrome.
I'm faced with a similar need since I'm going to re-convert my '78 R100S Touring bike to an S bike--as God and BMW originally intended it to be.
Back in the day, with BMW's collusion, Butler and Smith were scratching to sell BMW motorcycles. They concocted the so-called R100S Touring configuration which was intended to satisfy the American need for long distance high speed touring capabilities. Butler and Smith imported naked R100S bikes from BMW and fitted a color matched Luftmeister fairing to the bike. There was more to it than that since the bucket had to come out of the headlight shell and be put into the Luftmeister. Plus a special wiring harness had to be fabricated.
But in any event I've already ordered a painted and pin striped S fairing from Holt BMW. It will be shipped to me in a couple days. I'm fortunate because I already have some of those parts in the kit. Very importantly I have those ears that go onto the top of the forks. I also have the special long turn signal stalks intended for S fairing bikes, but unfortunately Butler and Smith bent them upwards to clear the Luftmeister fairing. It remains to be seen if I will be successful in getting them bent back in a decent cosmetic shape. Plus I have a few of the other parts (I think) in my used spares stock. What I won't have is the rubber grommet and retainer for where the fairing is mounted onto the turn signal stalks. But I have an idea for making my own, of a different design, which won't stand out like a sore thumb. The turn signal housings, after all, occlude the area a bit. Plus my USA bars won't work and I'm too fat and creaky for S bars. So I will have to locate a set of 22mm "Superbike" bend bars. The last time I checked a few years ago they were available.
The reason why I think I know so much about this is because I already have a sweet '77 R100S bike that I've already adapted to my needs with the superbike bars. It is my favorite airhead. When I get my ''78 R100S bike converted to S configuration I expect it to be my 2nd favorite airhead. (Points against the '78 include the hydraulic disc rear brake and the snowflake wheels.)
I am rich with the bikes I love!
Eratta: Chuey has talked about how to make longer turn signal stalks. That same tubing is used on the rear turn signal stalks, and I think maybe some BMW cowl mounted luggage racks. I've also discovered that the inside diameter of that tubing is just right for tapping with a 1/2-20 SAE tap. It also happens that U.S. lighting fixtures use 1/2-20 (female all-thread) hallow rod all over the place. This makes it possible to extend the existing stalks by adding a length of tubing and silver-soldering the joint with easy wicking silver solder.
I'm posting these ideas because Airhead riders tend to be a frugal bunch. (pregnant pause here) And there might be some possibilties for saving some money for people contemplating making up an "S" configured airhead.
Oh, did I mention that my '78 S bike is Smoke Red?
Ken