I picked up a used PPK/S in SS for about $450. All the work from Cylinder & Slide ran about $600 with overnight shipping both ways (the only way they'll do it). Just hope you're not in a hurry to get it all done, mine took 5 months just to get the O.K. from C&S to send it to them so they can work on it. Then I got it back about 6 weeks later. I asked that Ralph Gutekunst work on it since I read an article about a Glock he did in American Handgunner Tactical Annual (2004). After that when I sent e-mails to C&S, he was the one that replied to them personally.
I got these job codes done to it:
PP001 Throat bbl. and frame.
PP002 Radius and tension extractor.
PP003 Polish and deburr all internals.
PP005 Trigger job (mine came in at 4 lbs. 1 oz.).
PP006 Radius external corners and edges.
PP019 Recrown bbl. to 11 deg.
PP020 Novak fixed rear sight & C&S front dovetail sight (I had them put three white dots in mine).
Test fire and zero sights at 15 yards.
You can go here and price out the options you want:
http://www.cylinder-slide.com/pricing/walther_tun.shtml
And here is an excellent article about it:
http://www.cylinder-slide.com/combathandgun.shtml
I even went so far as to order the back issue of the magazine.
BTW- You'll have to ask them to put the C&S logo on the slide if you want it. I thought they did it by default but mine didn't have it.