Let's say I'm buying a cal. 861 Speedmaster that the seller says has been recently serviced, and because of this, will grant a 12-month warranty on accurate time-keeping. How much of a premium should this add to the price of the watch? Many thanks, M'Bob.
First off, don't EVER believe a seller, particularly an eBay seller, when they say a watch has been "recently serviced". What scale of time is "recently"..... glacial or galactic? I don't even trust all but a few people when I'm told a watch was "just serviced". Second, it's worth it to have your trusted watchmaker do a service so you know it's ready to wear. However, if the watch REALLY was serviced in the last year, I'd say it would add $200 - $300 to the value for a chronograph.
I have just had my smp serviced at swiss time services in the uk and because the bezel was scratched it cost £834 and has been returned in brand new condition. I would ask for a valid receipt of service !
If it had been recently serviced and there was paperwork to back this up, I'd be prepared to pay $200-300 extra, purely because I don't have the hassle of sending it away myself for several weeks. If it's from a private seller with no paperwork to back up the service claim, I wouldn't pay any extra and I'd send it to my watchmaker to check it out anyway.
If you had Rich Mille personally service your SSS then my answer would be probably a lot. in your example, you're not really buying the service, you're purchasing a (1) year warranty which is actually pretty valuable / maybe like 300 USD.
They grey marks varies. Was looking at Aqua Terras and found I could have a sizeable chunk off the price if I bought it sans the one year warranty