I would love to do a grad degree. Being a frontend/backend dev after coming out of a CS degree in uni is insanely boring, I feel like I'm barely using my brain

I would love to do a grad degree. Being a frontend/backend dev after coming out of a CS degree in uni is insanely boring, I feel like I'm barely using my brain at this point. But the opportunity cost is also crazy high in the current job market. Masters I can see but PhD would really set you back considering time value of money.