Sometimes you cant. Example: young player has rating 64. For level 10 he has 4 stars, for level 13+ he has 1 star. If he had been generated in 10 level club, he would be more expensive than on lvl13, because increasing level=decreasing value.
So if you want to buy two players that cost same money, you should buy one from higher level club. Of course, you cant know anything about club that sells player unless club's manager is your friend. You'll get info about players ex club after player arrive at your club.