For a limited time only, Microsoft are giving you the chance to have a second shot at any IT professional, developer or Microsoft Dynamics exam. Brilliant!
So now let me ask you – which one are you paying for? The first one, or the second one?
It may feel like you're paying for the first one, but don't be fooled. You're actually paying for the second one. The first is just a practice. A chance to get a feel for the exam, a chance to find out how to target your study. Don't lose sleep over the first one. If you use the product, don't even study. Just rock up and see how you go. When you leave, you'll have a piece of paper telling you the areas you didn't do so well, plus you'll know in your head that you need to study up about some particular area.
Don't consider that you get a free 'second shot'. Consider that you get a free practice exam, that comes with the bonus of giving you credit for the real one if you pass. The lack of stress in the first one will actually give you an increased chance. These exams are not a 'single-shot only' thing, like university or high-school. Accept that the first sitting is a learning experience, and pay for the second.