Well I'm pretty high lv which sometimes their isn't any good young players on the market so you have to go over 7-8 tokens otherwise throughout the season you'll end up wasting more on bidding players and not getting any of them.
Don't waste tokens on $$$ use them on free agents and then resell, through out the whole season you should get enough Boosters aswell. There's no reason to spend on this game when I challenge all the teams that do.