Think you've probably got a good little workhorse for the money M8. Keep on top of the chain with regular cleaning and a dry-setup lube to stop the dust sticking to it. Check it regularly for stretch and change once you notice any stretch (measure pin to pin on the links) as too much stretch and it will take out the sprockets - chains are cheap, sprockets and chain-rings aint!
Dry-setup lube goes on wet but dries to a waxy consistency within a few minutes. It's not quite as good as a wet-setup lube but requires less attention to maintenance. You can get both types from a decent cycle shop.
On costs, depends on quality level but say you go for mid to low-range Shimano then £15-20 for a chain. If the chain-rings are removable then about £15 per ring plus £30-50 for a cassette (rear sprockets). So, regular chain change is much cheaper
(I work in a bike shop )
Well seeing as some of you have posted pics...
Here's mine.
Specialized Enduro 2011 FSR Expert.
As for paying a shop or do your own maintenance, I do the basics of looking after it, cleaning and lubing etc, but anything more and I chuck it at the mechanics at work to fix for the usual charge of a couple of packets of biscuits
full carbon, what does it weigh?
I prefer off-road, a mate prefers batting down the roads - all good 
