I totally agree about staying away from Indian instruments and some Chinese (although they are getting better with supervision...) Trent Austin's own student brand is made in China and if Trent backs them, they must be decent. But the Indian instruments are called a trumpet-like-object for a reason.
This OP asked about a $600 budget trumpet. It isn't necessary for him to look for, settle on, a $75 cornet. I personally LOVE cornets because of their mellow sound. I have a new Carolbrass large bore & bell and a 1968 King Master copper (the best valves I own) and a 1980 Yamaha 232, just as Schilke designed it before their redone student line. I have a Getzen 3895 Custom flugalhorn too and appreciate everything good about it (valves, small bore, build quality wow) I would recommend a mint Getzen Eterna trumpet, That was one of the best so called student horns ever made! Now it's a step up horn and the 300 series is the student line
https://www.getzen.com/trumpets/ I believe Ingred Jensen plays a bronze Getzen Genisis
sorry, It's just that whenever someone says cornets are The Same as trumpets, I am forced to disagree.