Re: My sons saxophone
the Armstrong is a good student-intermediate model horn. It's plenty good enough to carry your son through high school, and even college. Is it an alto or a tenor? Alto repads usually run about $350, and tenor repads are around $400, so $380 is a little high for an alto, but cheap for a tenor. If they also replaced any corks or springs, $380 isn't bad at all.
If your son really enjoys playing and plans to continue playing into college, you may consider a better horn. I would suggest maybe waiting a couple years. If he's 12 now, maybe wait until he starts high school before buying a better horn. I'd say the Armstrong you have is very adequate for the time being