NHF – new heroes for Heroes V 3.1.

After talking with Nargott and considering a simple formula for the interceptor demon, we came to the conclusion that the following might work:
10*(Hero Level) for a level 7 creature, and for each subsequent lower level, it's halved (rounded up).
Example:
Level 15:
7 levels of creatures:
150
75
38
19
10
5
3.
Perhaps someone can suggest a simpler and easier formula that would also balance the stealing mechanic?