Hi Chaps, not wanting to hijack this thread and talk about my health and how things will be changing at JMG, I might start another one just to let people be in the picture...
But for this topic, we usually charge a fixed price of around £750 (from memory) for a head gasket replacement on a turbo, including the gaskets, seals and inspection as we proceed, but if there is a reason for it to be complicated for some reason, such as our investigation before or following head removal not showing logic that it is just the head gasket, this can turn into a "paying by the hour" job.. I think this has been our fixed price for about the last 10 years. I think Ewans turned expensive due to the car having complications, which turned out to be a hidden crack in the exhaust port, behind the ceramic and around the valve guide... Numerous tests, investigation and time were needed on that one, with eventually the whole head being scrapped as part of the repair.
For a head skim, we would recommend some caution, the head can only have a finite and a small amount of material removed via skimming before the compression ratio goes beyond a level where the engine will become detonation prone and you need to know where to measure the head to make sure you do not go beyond this skimming limit. We try to not skim a head unless it really needs it and then only by the minimum it needs to make it serviceable.
I don't think the price the original poster mentioned was at all bad, it also depends who did it and where they are based, you have to pay for knowledge, skills and kit, but also down here in Bournemouth for example, the costs of keeping the lights on and the workshop paid for are about the same as London and many times more than "Ooop north" and someone has to pay those costs otherwise the business goes under.
On that vein, all our prices are currently under review, and some things may be becoming more expensive and some cheaper as part of a reorganization which is planned in the very near future of how we do things.