I hope you do get into pines; they are a fascinating subject for bonsai. However, if you're new to bonsai, starting with pines is like taking up snow-shoeing by being dropped off in Antarctica. Continuing the metaphor; starting with $20 pines is like starting with $20 snow shoes.
I bought my first black pine in '98; a full 5 years after I started working with bonsai and killed it within a year. I attempted again in '02 and still struggled for 5 years with the physiological and horticultural responses to bonsai work. In '07 I went whole-hog into pines and it took a full 3 years of studying, practicing, and documenting work, to gain the confidence that I will get predictable results from my work, and I continue studying nuances of candle pruning, needle thinning, timing, etc, nearly every day.
Don't take this to mean you shouldn't buy pines...by all means, do. Just understand that the basic bonsai techniques are MUCH easier to learn on other trees that clearly show the cause-effect of your actions, and aren't as sensitive to timing of these actions.
By contrast, if an elm grows 5 leaves on a shoot, and you cut it back to 2, you can be confident that new growth is going to happen, exactly where it will happen; and timing is not very critical.