F35

Segway f35. Bought refurb for $250

Thats pretty light - you can use just about anything with a 350W + motor Probably your best deals are segway F series or Gotrax G Series

Im also a teen that commutes to school by escooter. Segway-Ninebot is a pretty high-quality brand in my opinion. For the purpose you gave the Ninebot E2 or E2 Plus II is a pretty cheap but still solid fit. I currently use the C2 Pro, its a kids scooter and Im very over the max reccomended rider age for it but I its cheap and gets the job done for me. But except for the few times I go somewhere extra, school’s only 1.8 miles for me, and for his longer range its probably better for him to get an E2, E2 Plus II, or maybe even an F-series if you want to get fancy (though I doubt he’ll need the power of an F-series).