Why do I need a business plan writer for my EB-5 project if I already know how to write a business plan?

A business plan writer who is experienced with EB-5 will have familiarity with Matter of Ho, RFEs, and other memoranda and guidance provided by USCIS. Additionally an experienced EB-5 BP writer should have some insight into what the market wants to see in order to be able to provide guidance along the way as well as to suggest when certain issues should be reviewed with counsel.

You can of course write your own plan, however, it is hard to find a comprehensive knowledge resource to ensure that you have a comprehensive set of guidelines to work from.

While you can write your own plan, you really do not want to make errors in that there are certain points that USCIS looks for when reviewing business plans. For example, one must be familiar with Matter of Ho and its requirements, as well as other administrative decisions and the like. It is best to bring in the best...there is no room for errors or delays.

Are you familiar with Matter of Ho? Here is a checklist I found online:
The plan should include a description of the business; the business' objectives; a market analysis including names of competing businesses and their relative strengths and weaknesses; a comparison of the competition's products and pricing structures; a description of the target market and prospective customers; a description of any manufacturing or production processes, materials required and supply sources; details of any contracts executed; marketing strategy including pricing, advertising, and servicing; organizational structure; and sales, cost and income projections and details of the bases therefore. In addition, specifically with respect to employment, the business plan must set forth the company's personnel experience, staffing requirements, job descriptions for all positions, and a timetable for hiring within the next two years.
It is therefore not worth saving a few dollars and write your own business plan exposing you to undue delays because of errors in format, content or both.