Re: the fee
I've long been of the opinion that we should target players in his category and that we should be willing to go far in terms of transfer fees (as we did for Martial).
There's a risk involved, that goes without saying. You could end up with Ando, sure. But if you do your homework and target more right players than wrong 'uns, it's a sound strategy. We don't have a financial edge on our rivals (or what should be our rivals) in terms of outbidding them for established and recognized top players (of the marquee variety). But we do have significant means - and we can outbid our rivals for players who are not established and recognized.
A variation on the Wenger strategy of old, but with less risk involved (since the players in question are, if nothing else, recognized top talents - as in, Golden Boy territory).
Anyway, as far as personal preferences go, I'd rather have us pay grotesque sums for young talents than offering huge salaries to marquee types (not to mention marquee types who are over the hill, or getting there rapidly).