Is it wrong for me to want a 'horse'?

So, I've been riding this 5 year old 16.2hh Quarter Horse gelding regularly for a friend who wants to make sure he's well behaved before she works up the courage to ride him... and I hate to say it, but I love riding him.
As you may know, I've had only ponies under 14hh my whole life. I've ridden different horses, but only owned ponies because they just suit me really well size-wise, (I'm 5 feet tall and don't even break 100lbs...)
The 2 ponies I have now are Star and Specs, and I absolutely adore them. Star is a Shetland (don't worry, I don't actually ride her, lol!) and Specs is a just barely considered a pony at exactly 14hh...
Back to the topic, I just really feel like I would have fun adding a big horse to the mix... Is it bad for me to want what I don't have? I also don't want to devote all my riding time to a horse, when I barely have enough time for the two that I have.
Another concern that I have is about the money. My parents aren't opposed to me getting another horse, but they are trying to teach me the value of a dollar, so if I want this new horse, I have to pay for it all myself. Not to say a number, but I'm too young to get a job legally so there's no way I'm going to be able to buy a $2000 horse.. More like under $800 if I'm lucky. And if I'm correct, that'll buy me a green unregistered 4 year old, and that could be a potential disaster. And leasing wouldn't work out given that I don't go to an actual riding barn, I have my horses at home... *oyy*
I just don't know. Should I go for it? Is it bad that I want a different horse? I'd like some advice...
Thankyou.

"Is it bad for me to want what I don't have? I also don't want to devote all my riding time to a horse, when I barely have enough time for the two that I have."

It may not be bad, but it sounds unrealistic. I have a lot of "wants", but my cash only allows for "needs" and some "wants".

Time is also a limit. If you barely have enough time for the ones you have, then adding another is likely to work out bad.

I was 50 before I had enough money to own horses. If you add one at your age, then who will take care of it when you go to college or get a job? Once you leave home, you will have less time, not more.

Not to go all high and mighty on you, but people want what they don't have.

If you have the money and space, go for it! But it sounds like you're already struggling..
Horses are a lot of fun :) Maybe you could start leasing him from your friend as a second option.

Wait till you can pay for it. I saved every penny I earned, bought a horse at 15, worked every evening and weekend to afford board, farrier, vet bills and tack. I'm in my mid 20's and I still have horses, but its not been easy. No one has ever paid a penny towards them except me. I've always paid for all my own Bills, rent, food, car, travel expenses, etc. My parents never had the money to help, and I never asked.

Enjoy your ponies, when you can get a job, save your pennies and look at getting a horse then.