Worth the purchase
This product gave me a reasonable expectation of what the LSAT would bring and I did well.
Not the most cost effective, but definitely helpful
If you're just going to take a few official prep tests, then grab the latest ones availble such as this one. It'll be closer to the real deal than some of the older tests, but not that much different. However, you're best buy is one of the books that contains 10 prep tests instead of only 1. 1 test = 8 bucks, 10 tests = ~20 bucks...you do the math. If you have the time to take multiple tests, then grab one of these:
"10 Actual, Official LSAT Preptests"
"Next 10 Actual, Official LSAT Preptests"
"10 More Actual, Official LSAT Preptests"