The problem with PCP's is the cost of the support system. You can buy a hand pump, but I hate pumping and it's not easy to hit 2800 PSI. Takes a lot of work. In the case of my Marauder, it's 3 pumps per shot.
Bottles cost about $350 for the 98CI version, then you've got to have a place to fill it, like a paintball shop. That $350 is most of your budget.
So, the $450 budget puts you in one of two camps. Entry level PCP, which the Maximus in a kit including pump, or a higher end break barrel. There are some good break barrels out there, but firing rate is slow.
The Maximus is a small cylinder, with a only 2000 PSI fill, so easily hand pumped. Check out the reviews. Crosman has a kit including a pump on Crosman.com that can be had for $265. That gets you up and shooting ASAP. $350 kit, -25% using the AGNATION code and free shipping on Fridays. Check out AEAC's reviews.
The maximus will last for years, and the learning curve of a PCP is, well, minimal. No recoil at all, so that harsh double recoil of a break barrel isn't there. Also means you can put any scope on the market on the gun and the recoil will never damage the scope, 'cause there isn't any recoil.
Having had break barrels and a couple PCP's, I can't go back. I'd take an inexpensive PCP over a break barrel any day, but everyone has to make their own choice.
Higher end break barrels are out there, but I can't speak to them. Others love their guns, but I'm into PCP's
The problem is that it doesn't matter which you buy, you'll be bit by the bug and want more (don't we all?) Your budget for the next gun will increase dramatically and you'll want better and better. That's just the way it works.