Welcome and thank you for your question!
Based on what I have seen in practice, the expenses in your example are a bit low compared to average. It should be noted, however, that net income from self-employment can vary widely depending on many factors, such as industry and age of business. Start-up businesses, for example, typically lose money at first.
The IRS permits deductions against income for any expenses deemed "ordinary and necessary" to the business. A careful review of form schedule C might review some items to deduct that you may not have thought of already.
I found a link to some IRS statistical tables you may be interested in reviewing:
When the evaluators take six weeks of "earnings" perhaps they will be taking net income and not gross income. You indicated that you "assume" they will factor in a percentage for expense deductions. It seems to me they would take your net income rather than try to back into your net income based on gross earnings. Every business is different and even within businesses in the same industry and the same size, there could be widely different results. Businesses are like snowflakes and fingerprints, all different and unique in their own way.
The best argument you could make in your favor would be to show them a copy of your prior year tax return, as filed. Sometimes a letter from your CPA to go along with it is a slam dunk. We have prepared numerous letters for self-employed clients stating that the client has been in business for X number of years in X industry and has consistently reported the revenues and expenses of the business on their tax returns.
The only other advice I could provide is to ask the agency you are applying with to provide specifics as to how they will calculate your net income. You should be able to access their statistics and argue the credibility of them at that time. If they do in fact use statistics to calculate your net income as you indicated, they will need a well documented creditable source, to which you can use also.
Thanks for the question!
IRS Circular 230 Disclosure:
Any U.S. federal tax advice contained in this document is not intended or written to be used, and cannot be used, for the purpose of (i) avoiding penalties under the Internal Revenue Code, or (ii) promoting, marketing, or recommending to another party any transaction or matter that is contained in this document.