I have some base level automations and table links created, but I am now experiencing difficulty creating further links.

Three main tables: Students

Class List

Class Price

Current links: Students to Class Lists. Class Lists table has hours per class. Based on classes students are put in (in Class Lists), it changes their total hours (in Students). On Students table there is a Roll Up that calculates total hours students are in based upon their Class List. 

Class Price table is connected (vaguely) to Students table, but establishing the correct link to make things work is not happening in my brain. 

I want to, based upon the Roll Up hours in Students table, have students automatically assigned to that specific number in the Class Prices table and/or have the dollar amount assigned to a total hours on the Class Prices table to be placed in the Students table, so it can easily be seen how much they own either monthly or by semester.

So far, I can have it create a completely new record (which I don’t want) in the class price table.

Do I need to create yet another junction table to make this function properly? Or is there some sort of automation step I am missing?

Current automation I’ve been playing with (though it is not actually adding in students to the Class Price table):