Let's be real, we're not going to sign the likes of Lewandowski, Falcao and Cavani. The best clubs will see to that and even the players will think twice - even if we match their wage demands.
Our best hope is to find players who look like they're going to threaten to break into the big time and sign him. Even if costs us 20m-25m.
You could argue that's what we do with someone like Giroud and Gervinho, but Jovetic is of a considerably high profile imo.