Yeah, as others have said, I would spend much more than $300 for a guitar and amp for someone who has been playing guitar for that long. However, only you can tell us if it's a hobby he truly enjoys.
Guitars are also a very personal thing. Reviews and recommendations from others are irrelevant, unless you are talking about objective aspects. For Christmas in 2005, my dad did it right for my first mid-range guitar. I came home from my first semester in college, and my dad surprised me by taking me to the large Guitar Center in Dallas to go guitar shopping. That allowed us to look together, and allowed me to play several models. Strangely enough, I ended up choosing a Schecter S-1 Elite.
However, I didn't actually get the guitar until Christmas morning.
Kind of funny now, because I wish I had gone with a Les Paul Special, but I was 18 and went with what looked cool for an 18 year old.
If your son doesn't see his guitar and love how it looks, he will not pick it up as much as he will if he loves the way his guitar looks. It also needs to feel great in his hands. Everyone has different preferences on neck thickness, scale length, etc.
ETA: The Schecter my dad bought me was $650 at the time, brand new. That was considered "mid-range" and still only came with Duncan Designed pickups, so they were cheap and eventually needed to be replaced.
If he's not opposed to the idea, buying used guitars is the way to go. You will pay 50-70% the price of a new guitar, giving you even better options. For example, I recently bought a Fender Custom Shop Telecaster that would probably cost me $4,500-$5,000 new. On Reverb, the guy I bought it from accepted $2,800 for it.