Going by prices of my local few shops that do alot of VW's etc.. For a good job too, not a cheap one.. around £800 for an exterior respray in the same colour.. Around £1000-1100 if you want to include the door shuts, top of the inner wings and boot shut. Also im not sure what Glanza's are like, but in my Polo, the rear side windows need to be removed for a proper spray cause of the exposed rubber seals, which make it a mission to mask off. Change of colour would be the same price, either way the car needs to be flatted back down so it doesnt make much difference what colour goes back on top. Thing is, if you need scratches, stone chips and any work like that included, it will knock the price up as it's just more time consuming. It always helps if you can do as much prep work as possible yourself, but only if you know that it will to a good enough standard for the shop to work on. I for example, needed my bonnet repainting due to loads of stone chips. Would have been alot of prep work as it needed putting back to bare metal. Something like that you could easily do yourself, either buy a spare bonnet without chips, or put a spare on your car and prep your own. Just a case of sanding the paint down through the grades until the bare metal, then whack some etching primer on. Prep work is always the most time consuming and therefore affects the price drastically. HTH.