According to the Wiki the Skill Tree is Fairly Extensive in how much Points you need.
So you need to have the Parent Skill on 60 to get the next Skill over 30
And the Skill Trees go up by 4 Tiers
So For example.
Thats
60+60+60+100
Total of 280
But we only get 210 Skillpoints.
So how does this even work ????
With this getting more than 30 in the Tier 4 Skill would be Impossible