It doesn't really answer your question but I thought id chuck in my 4 penn'orth regarding the apparent values of cars on offer.
I paid a big premium for my 2007 Gen 1 C4S Cabrio manual from OPC a year ago. I have been looking at prices simply to see what sort of "investment" (howls of laughter!) it was and my conclusion is that, as you are finding, 997 prices are heading South quite quickly now, if I sold privately I would probably struggle not to lose 8-9k, though i am keeping this one
Our car had done 33k - now 36k -and had the OPC 111 point check and was sold with a 2.5 year warranty..... the sunlit uplands beckoned.
In the last few months it has had a major service, plus, as recommended, new plugs, 12 yearly transmission/4wd oil change, clutch, DM Flywheel which were all paid for by me and the A/C condensers replaced under warranty. All done at OPC - ouch! However these should keep me going for some time though pads and discs are next on the agenda... not ceramic thank god.
Service prices I have paid have been in excess of those suggested in the buyers guides, even including 10% PCGB discount but ive decided that I'd suck the mop and try to preserve what value is there, and I can sleep at night, so in essence, the car should be a corker, but i'm under no illusions as to where the value is going, and it ain't up. But i think the service costs i am seeing for my age of car is being built into selling prices
The 997 was the last 911 under Porsche ownership and some believe it has some Kudos for that but it isn't going to make the standard cars any more valuable is it? I'd be interested in any thoughts. 996's are nose diving even further - and i think there may be some genuine bargains to be had if you are very careful.
In short Pete - I wouldn't hang around ....