The problem today is that teams are buying players that never would have been sold in the past. There was always transfer activity, but the sheer number of top players shifting teams each year is ridiculous. I mean some of them would have been sold, yes. But rich teams now will just raise their offers higher and higher until it is accepted. Monaco didn't need to sell Martial, probably didn't want to, until ManU made them an offer that would be ridiculous to refuse. Same deal with ManCity for DeBruyne, Madrid for Bale and Rodriguez, Barca for Suarez, and so on. They're willing to pay basically whatever it takes to make their offer impossible to refuse. It makes the market absurd.