Great observation: well done! There are two aspects to this:
1. Our Setup
We price our Sanity Checks, Strategic Essay Reviews and Mock Interviews based on the expectation that someone has already gone through the advice modules in the Lab in-depth and thus we're able to focus on helping you REFINE your story vs. helping build it from scratch (which would obviously take several, several hours and would thus have to be priced accordingly).
BECAUSE you've done 90% of the work yourself, your materials are already in MUCH better shape than they would be otherwise, and we're able to more efficiently give you value-add feedback in less time that it would take for us to review "raw" materials (and time is money!)
2. Business Decisions
Most traditional consulting firms only pay ~50% of their "retail" prices to their consultants and keep the rest for themselves (for marketing expenses, overhead, and profit margin). In other words, the firm charging YOU $350/hour may be paying the CONSULTANT you're working with $150 an hour and KEEPING $200/hour for themselves.
Since we run a very lean operation overall (and are just less greedy), we pay our consultants similar to how they'd be compensated at a traditional firm and pass the "savings" on to YOU in the form of lower prices - keeping in line with our mission to provide AFFORDABLE quality advice that is ACCESSIBLE to all.