Your power supply should act as a surge protector. IE, it will blow out, not the laptop. This is also true if you forgot momentarily what country you’re in and plug it into a socket w/ the wrong voltage.
However, the power supplies can get costly themselves, as they are almost always some bullshit proprietary connection. The Mac ones, for example, are in the $100 range. I’ve seen PC ones closer to $200.
Laptop-powered setups are quite save, when something comes down the line that’s too much for your PSU then even a surge-protection would save you. For External mixers and stuff, it’s a different story. Same with external powered USB-Hubs etc… I got a powerstrip with surge-protection from APC, never needed mine until now knock-on-wood