Consider adding additional checks when setting billing config values

[krebernisak]

Which configs here need to be scaled, please be a little more specific here.

Can we do a quick and safe sanity check on these configs on the input so we revert if:

• values are really low (not scaled properly)?
• values are under contract defaults, does it make sense to go under defaults?

Originally posted by @krebernisak in #36 (comment)