It's up to what your objectives are really bud.

I'm a token buyer, but not to the extent of some people who play.

I buy a few scouts every season, so my average quality is extremely high for my level, scout actually.
Because of this, I'm usually guaranteed to win the league and have a really good chance of winning the champions league, but I have NO chance in the cup, I'm level 4, I played a level 7/8 cup.

If you fancy getting a Nordeus Cup in your trophy cabinet, then you may want to save a load of tokens, and wait until you get a fairly easy cup draw, then spend your tokens on power training and scouts, and smash the opposition.

Otherwise, you can spend them regularly to maintain a good squad every season, and go for the double trophy hauls.

That being said, there are people out there on a 35T budget, who challenge for all 3 trophies, so it's all about spending wisely.