It's not just the individual quality he'd add to that pile of shit that bugs me, it's equally the message it sends. It's one thing selling has-beens like Adebayor and Touré to City for a huge lump of money. Nasri could well end up being the french player of his generation though and is coming off a strong season, and he's nowhere near his prime yet. To lose him over £20 000 quid a week and then having to find a proper replacement who'll just end up earning close to that sum anyway is imbecile, to put it lightly.
The most frustrating thing of all is that we don't even need to spend huge sums to reinforce the attack. Just keep the players we have and go for someone like Young to provide depth and alternatives. Even Gervinho will improve us, provided that we keep what we already have. We don't have to sign a superstar to improve. We just need to make sure that we're not so damn reliable on two-three players to make stuff happen in the final third.