Volume 3, Book 34, Number 315:
Narrated Anas bin Malik (radiallaahu `anhu):
Abu Taiba cupped Allah’s Apostle (sallallaahu `alayhi wasallam) so he ordered that he be paid one Sa` of dates and ordered his masters to reduce his tax (as he was a slave and had to pay a tax to them).
Volume 3, Book 34, Number 316:
Narrated Ibn ‘Abbas (radiallaahu `anhu):
Once the Prophet (sallallaahu `alayhi wasallam) got his blood out (medically) and paid that person who had done it. If it had been illegal, the Prophet (sallallaahu `alayhi wasallam) would not have paid him.
It was briefly mentioned in a previous post that it’s not exactly haraam to charge money for Hijaamah.
Ibn Qudaamah (may Allaah have mercy on him) said:
It is permissible to hire a cupper to treat one with cupping, and his earnings are permissible.
Go through the detailed discussion on the subject here.