Hi itsmedavidv,
There are plenty of options when it comes to studying for the GMAT and there's a considerable range in prices. Ultimately, you're looking for the right combination of resources that helps you to hit your score goals in a timely fashion and at a price that you consider acceptable.
Most GMAT companies offer some type of free resources (practice problems, Trial Accounts, free videos, etc.) so that you can "test out" a product before you buy it. You should take advantage of all of these freebies, then use them as a gauge for whether you improve or not. Choose the one (or combination) that best fits your personality, timeline and budget.
What is your score goal?
When are you planning to apply to Business School?
GMAT assassins aren't born, they're made,
Rich