Manchester United are great at spending money in the transfer window but their ability to sell leaves much to be desired. The net spend of the Red Devils over the past decade does not make for pretty reading. Under the Glazers, Manchester United have had an embarrassing number of transfer flops – some of which are still at the club. There can be no complaints over the amount of money spent, more towards how it has been spent. United certainly don’t compare well to their Premier League rivals when it comes to profits from sales, but there has been a noticeable improvement under new ownership. D…