Don't spend a lot. Most people don't stick with it.
The tuner is a good idea.

Be sure to get him 2 months of weekly lessons.
Make sure the teacher can show him tunes he likes.
Doesn't matter the genre, just simple 3 chord tunes.
Get him hooked on the instrument. If he likes it, he'll do the hard work.

Don't start him off learning "The Volga Boatman" from Alfreds Basic Guitar Method.
He'll quit in a week.

In my years of playing noone has ever called for that tune, either in the audience or from the bandstand.

Now "Blue Tailed Fly", that's a story for another time.

biab2023(Mac)
Logic Pro X