I think city selling a player for good money is a fantasy. we can't do it ( Negredo deal sort of I suppose). tbf, look at the fees united are getting for their departing folk. Van Persie, toast of the league just 18 months or so ago is now being shoved out the back door for 4 million. Elite clubs often have this problem.
Chelsea sold a few for big money purely because pre-mourinho they signed players to play attacking flamboyant football and then jose got there and was like nah mate, so they had plenty of young elite players to sell. Otherwise it will be more of this tbh, frankly 14 million would be impressive by our recent strandards