The trouble with a candy is, apart from the material cost, the time and the risk of fucking it up.
Basically you spray a metallic base coat and then the colour coat goes over the top. The amount of colour coats affects the shade. Therefore is you ever need to do a repair or blow in your pretty much shafted. You also need the prep to be spot on so your labour cost will be pretty high.
It wouldn't surprise me if theres like £500+ worth of candy paint there. Plus your looking £2000+ for a respray. And thats not accounting for any other repairs that need to be done prior to priming up.
(and yes we've done more than a handful of buses that "don't need any welding cause its solid" and still spent a couple of days with the welder out before we got anywhere near a spray gun)