What's holding you back from not taking 100% of the balance after recovering it?
Literally nothing if we're going to be honest. Especially when the one who offers this kind of service has no reputation on the forum and his account is worth nothing.
In addition, if someone has a wallet that is protected with a strong password, the chances of unlocking such a wallet are practically zero, unless the owner cannot remember some details of his password. However, it is possible that someone has found a way to
"extract" such passwords in some other way than through the brute force method.