Laughable really. We never seem to aim for players at clubs that are on our level, bar Lukaku as an exception.
mainly because players don't make sideways steps in their career, unless they are at that bottom of the premier league standard. we aim lower because there are better bargains, something we need to do with our finances.
for example, you look at someone like dembele and you think he's a great player, would work nicely here, but if he's not getting in a spurs team which is no better than ours (i'm discounting this league season so far as i have no idea what we're doing), then how will he actually improve us. when selling to a league rival you're not going to want to strengthen them, but it will take a silly offer to make you listen. whereas a lower offer from a team you don't consider a rival, will be more appealing.
look at mata to united for example, great player, but not worth £40m, only that silly amount of offer that made chelsea want to sell and if united were up there with them they would have probably turned that down.