Wonderful cars. Not all that quick (at least in 1.8 or 2.0 spec ) but the build quality is fantastic. Some poeple will say they arent as good as the really old mercs, but head over to the mbforums and most people agree the build quality is a lot better than the new C class, and many say also better than the 190 it replaced. I borrowed a mates focus 1.8 ghia today and it felt horrible cheap and plasticky inside compared to my C200 elegance. His car was 6 years younger than mine and was full of rattles and just generally felt like a budget car, whereas the merc feels solid and full of quality in every little switch. ignore the people that say you are buying a badge. Mercedes have earned that badge for a reason - they make fantastic motor cars. Yes, they had some serious quality control issues in recent years (and the modern C class is built in South Africa compared to the German factories of the old ones) but you're not looking at those cars anyway.
My main advice would be to not let your heart rule your head. Theres a saying that nothing is more expensive than a cheap mercedes and that can be true. However, its more a case of how well its been looked after. Dont touch anything without a full MB or specialist service history. If theres any gaps assume its been clocked and walk away. I had to look round loads of cars before I found a real peach - 1997 C200 for £1900 with FMSH and truly immaculate condition. Got a few thousand on it now and its cost me nothing to run so far apart from a cracked windscreen. The whole car just felt right - meticulously well looked afetr, totally original and unmodded and basically feels like driving a new car.
The good news is insurance is cheap as you found out (only £250 a year for me
) and theres a decent supply of parts to be found on ebay. There are also plenty of examples so you can choose to be picky. Even better news is apparently they are tipped to become quite sought after, so get one in great condition, keep up the service history and you shouldnt lose much on it at all.
Oh, and make sure you go for an automatic - the manuals dont go very well with the foot operated parking brakes and hence are difficult to resell. The autos are smooth as silk and allow a very relaxed drive, which is as it should be. I personally wouldnt put all the AMG kit on a C180. It will make it difficult to sell on and embarrassing at the traffic lights! Just enjoy a bit of lower end MB ownership and buy a C43, 4.3 ltr AMG when you can afford the insurance and petrol. Awesome cars and you can pick them up for about £5k, which is pretty good for a 300bhp motor