Is the punishment for one who masturbates once or twice a month, then regrets it, and maintains their prayers and recitation of the Quran, the same as the punishment for one who masturbates daily?

Your friend must offer sincere repentance and completely abandon this blameworthy habit. The door of repentance does not close for him, even if he repeats the sin, for Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" Sincere repentance erases sins, and one who repents is like one who has no sin. He should not take someone worse than him as an example; rather, he must feel remorse and repent, and look to the greatness of Allah, not the insignificance of the sin. He should look to those who are better than him in religion to emulate them and compete with them in acts of obedience.