what does the joke sam beakwon mean?

200 prounounced ibaekwon in korean sounds like leebaekwon (uke) + 100 (half of seme aka his pp) = 300 pronounced sambaekwon (pp inside uke)

It's a joke from chapter 50
Lee Baekwon (200 won) is Yoohan's nickname
Sam Baekwon (300 won) is, as the boss puts it, Yoohan with Jay's dick up his ass