Keep in mind that you get what you pay for with certification training materials. If you want to just grab braindump material on the Web, sure, you can pass the test... But to really LEARN the concepts, I would suggest doing some hands-on work, reading some good study materials, and take some practice exams that offer detailed explanations of the concepts. I agree with you - the explanations make all the difference in the world.
As far as deals on Transcender software go, be sure that you're purchasing ONLY from a Transcender Authorized Reseller (or directly from Transcender). You might want to check out the
TransCram 30-day Online Access deal from Transcender... it'll save you $16 over the download version.
All that being said, I'm glad the Transcenders for 70-210 worked for you, and I hope that you'll consider Transcender for 70-215. After all... I'm not only a user of Transcender products... I'm also a Transcender developer.

Let me know if I can provide any assistance.