As discussed in a post I started a week or so back, Grand Prix is a very flexible term. It just means there is prize money attached. One of our local shows did a $5000? Miniprix at the 3 foot level.
The real question is about height of jumps and circuit.
And not just whether your horse can heave himself over one jump at that height but whethet he can do a course at that height. The jumps get more technical as well as higher.
OP are you currently showing and winning or placing at the 3 foot level? And on what circuit, IE schooling shows or A level or what?
If you are doing well at the 3 foot level the question to ask your coach is how to move up in height.
But really it is typical for most people to learn to jump on a horse that starts to get maxed out over 3 feet. When they’ve topped out at that, they go looking to buy a higher level horse with the help of their trainer.
Around here the lower level horse would typically cost $5000 to $10,000 and the next level could be up to $50,000, if you are after a confirmed competitive horse. Of course talented riders and trainers do also start with free or low priced OTTBs or other young horses.
OP, these are questions you should ask your trainer. If your trainer won’t have this conversation with you, is it because trainer feels you are miles away from moving up or is trainer not qualified enough to know? In that case you need to approach a better training barn to ask.
I should add though that in sports as in arts, talent counts for a lot and the pool of competitors narrows a lot ad you go up.
If I asked what is the realistic process to become a pro basketball player or a pop music superstar, I think we’d all recognize that raw talent visible at an early age, a strong work ethic, and a bit of luck all play into it.
This is different from success in the professions where the answer is go to law school or med school and do OK.