She appears to be cute and able and a useful sort of horse.
The second photo is the best in terms of her form; with knees well up and nice and tight below. However, she is what Americans would call a "splinter belly" jumper - she jumps very flat, with her belly the lowest point of her body, rather than rounding over a fence and showing a bascule. This will limit her scope, she will probably start to struggle a little as the fences get to the 3'3" - 3'6" range.
The third photo is either taken a little late on the downward part of the arc or she got into the fence wrong, or both. Doesn't flatter either of you; except that I really like your release in that photo.
Can't give you any opinion on price, sorry, as I have no idea what horses go for in your area.
For someone who's self taught your form is excellent. I would like to see you carry your stirrup more on the ball of your foot, at a slight angle with the outside branch ahead of the inside. This will allow more weight to travel down into your heel and refine your leg position. I'd also like to see your hand and arm come a little more forwad in your release in the first and second photos. Other than that, good working functional position, good automatic release.
The flat photo isn't great - you need some weight in the heel, and to straighten your shoulder slightly. You also need to shorten your rein and carry your hand and arm out ahead of you more, with thumbs up and maintaining a straight line from bit to elbow (This is actually better in the over fences photos.)