I agree with the others. I am hearing too many contradictory things in your own posts here.
Yes, of course a good barrel horse is going to be expensive. The same way a good reining horse or a good western pleasure horse or a good tie down roping horse would be expensive. Someone put years of training into the horse to make it good -- that is worth something. If you send a horse to a trainer (a cheap one would be $300 a month) for 3 or 4 months, you've already dished out a minimum of $1,200 in training toward the value of that horse. Plus, a good horse can win some big bucks at big rodeos.
Of course untrained horses cost less. They haven't had training or someone sticking time and money and experience into them. They don't know anything!
How do you know if a yearling is good at barrels, or any other event for that matter? You don't. It's a yearling. However, bloodlines can play a factor and if you are wanting something that's most likely going to be a top-notch NFR horse (potentially), expect to spend at least 5 figures. Yes, 5 figures. Although in this horse market, it is possible to find something with decent bloodlines for under $1,000. It won't be top-notch bloodlines, but it will be decent.
If you don't know anything about bloodlines or confirmation, start reading up. Barrel Horse News, the Barrel Racing Report, and many more are good sources. Western Horseman, Equus, and Horse and Rider are just a few good general horse information magazine. And if you are going to go look at a horse, do your homework before hand. Ask others you trust and are well-educated before you go, and/or have them help you make a decision on what to look for. You can also get your hands on books and DVD's by some of the greats like Charmayne James, Sherry Cervi, Dena Kirkpatrick, Martha Josey, and more. Not only do they go over how to train a barrel horse, but they will talk about important things like bloodlines, conformation, looking at prospects, hauling, tack, and more. Get into some resources if you want to learn.
I'm very confused with your tone as you say you know what you are doing because you've trained a few 2D/3D horses in the past and don't want to fix other's mistakes, but yet you don't know what to look for and don't know if the horse has bad habits. I don't think that's the best tone to take. From what I've read in just this post (I haven't even looked at the others), I'd say you are toward a beginner barrel racer due to the sole fact you don't seem to know any general horse background. I am not saying that's a bad thing, as everyone on this forum was there at one point in time, but you need to come to terms with that in order to learn and to grow.
CLaPorte432 is exactly right.
And if you can't afford a trained ready-to-go barrel horse, you can always try to find one to lease, which is usually cheaper.
∞•*˚ Βгįťţαňγ ˚*•∞
It is not enough to know how to ride; one must know how to fall.