I have one ball for the "star player" category for the last 3 or four seasons and always have been above seoason average for merchandise.
I try to have as many NT-players as possible on my roster, that gives you some few k per player extra. While it is hard to buy NT-players from big countries, there are plenty affordable and reasonable players (like ~150k centers compared to the 400k+ monsters from bigger communities) on the market every week.
I have two drafted players on my team that both were in the U21 that seems to have helped too.