Granted it has been nearly 2 years since I worked at TDS but the prices were the same as the park (actually at that time it was a little cheaper because the prices hadn't been updated in the computer and we were selling them at the old prices before the rate increase) but my favorite thing about buying tickets at TDS is that you can buy one (that never expires) and put it away until you can afford another, and so on. So you're not stuck buying passes for everyone all at once and helps to make your Disney experience more managable cost-wise.
Cheryl