It's what Lyon and other big clubs (but clubs not quite in the elite bracket) have done well over the years. Sign for reasonable fees, raise the player to a better standard and then rinse any buying club for a small fortune. Which keeps the whole thing rolling.
You want to bid for our better players?
Fine. But it will hurt.
All that said, I don't see him at Tottingham. For one thing, Levy will probably offer Eric Dier, Joe Hart and a pack of Murray mints from the back of the sofa.
Smart businessman? Bollocks. It ain't smart business when you consistently can't complete the deals you want to do.