I normally don't add comments after I've provided my guidance unless there are further questions, however, I felt it important to add to this post for the original requestor. Putting myself in your shoes, these responses would make me feel like it's a contest for best sales pitches instead of advice you can actually take away without signing up for services.
The notion that pricier professional admissions service is tantamount to the best service and cheaper service is equal to bad or less than good quality service is simply false and misguided. Often times, folks that charge you more for the same services do so to cover their overhead costs and the cost of paying their employees, etc - this is often the case with the larger admissions consulting companies. Finding good professional help for MBA Admissions is not like buying designer shoes. The formula of the more money you pay the better the quality you get doesn't quite work, at least not consistently enough to make this generality a true statement. I agree, you should read reviews as a general guide but more importantly get referrals from trusted friends and go with your gut when you have spoken to a professional to ensure it's a good fit for you.
Putting my consultant hat aside and drawing from my own previous experience as an MBA applicant, I understand where you're coming from and acknowledge that not everyone has the means to pay the market prices for these services even though they do often make a big difference in your chances of getting admitted. That said, do not let that discourage you from finding more affordable (or free) options. Reach out to the schools you're interested in, attend their admissions events, ask to be put in contact with current students and alums. You would be surprised to see how many people are willing to help review an essay or give you valuable tips; I have done so a number of times for my alma mater. There are other programs for minority groups such as MLT.org that provide assistance as well. When there is a will, there's a way and I'm sure you will find one well suited for you AND your wallet
Best of luck.