Hello Umbra!
Well there are two different types of disciplines, Passive and Targeted. Passive disciplines don't target anyone, just yourself and they are cumulative meaning they build on top of each other. Targeted disciplines are just that, they target others (ranged).
For the Passive disciplines, you will want to open the file \vdata\system\stats.txt with notepad.exe. As you scroll towards the bottom you will see entries on how much blood costs are for the Passive disciplines. Change those to what you want and save the file.
For the Targeted disciplines you will want to find the file \vdata\system\DisciplineTgt_xxx.txt (The xxx will be 000, 001, 002, etc...). Open up these files with notepad.exe and you will see the cost and durations of these disciplines.
Play around with it and if you still can't get it feel free to write back and we'll try to help you further.