I've only recently joined and I haven't spent a penny on tokens or booster packs I get all my tokens and boosters from app downloads, videos, surveys and playing online games for set amount of time it's a bit of chore but you do get free tokens at the end of the day.
I've used some of my tokens to speed up building projects which in turn will give you additional revenue and I've spent some for additional signings to strengthen my side.
I'm always looking for free agents under 21 I keep them for a few days these signings are totally maxed out on training you can make some tidy profits if you're smart ;-)
I signed one player for 2k sold him for 850k 2 days later.
I now have the strongest side in my league hence why I'm top of my league