On a vehicle of this age (to me) FSH means it is serviced every 10,000 miles or once every year which ever comes first - thats how I do mine - I do less than 10k but i still change the oil once every year.
However since the missing services go back may years ago I would overlook that and judge the car on its condition and drive. I would also factor in a Timing belt and waterpump change very soon into the price. As phil says £2k would sound about right.
The air struts are very reliable on the 430s - I would get a second opinion on the "misting" mentioned above.
It certainly looks very tidy and the seller has taken an enthusiastic approach when wriring the advert which is a good sign.