Jeremy's IT Lab Practice Exam Vs. Boson Exsim

I was getting ready to purchase Boson Exsim for $100 when I just now found out Jeremy's IT Lab has a practice exam for only $10. How does His practice exam compare to Exsim? If the point of ExSim is to gauge if you're ready for the exam or not and I can do that for $10 instead of $100, I'd like to know so I can save my money, because I'm tight on funds right now.