Lots of choices for under $400, amazing how many.
Back in the day, you either spent big money or wound up with a horrid little 'Spanish Geetar' from the stamp catalog. I wonder how many careers started with the little Silvertone electric with the accompanying case with the amp built in?
I'd REALLY agree it needs to have good action.
After that I'm always torn between buying something heavier since it's gonna get beat up vs. buying something nicer so you can get some of your money back when he decides he wants to play sports instead.
Plus you have to ride that line where you can get something he thinks is cool vs. the one you bring it home and he just rolls his eyes and wouldn't dare show what YOU picked out to his friends !
OK, go with nicer. Big Baby's certainly a safe bet. A 'starter' Larrivee for under $400 would be a gas, maybe one of the Mexican Martins. People still start on Yamaha boxes, a black F335, $149, all laminate, or the solid top, rosewood back and sides FG730S thru Musician's friend or local retailer is hard to beat for $299. But there's lots out there for a $400 budget.
J o e y