I think using any of these average prices paid as the basis for a business plan would be ill advised they are industry average figures that hardly apply to the individual.
As a Northern Hardwood sawyer for 22 years, I know that the individual log determines the grade yield. The grades may differ wildly depending on every little variable. The tables and statistics are averages, and by basing business decisions on those, and not real experience with the local timber, markets, soil types, (Mineral can kick the hell out of ya) etc, in my mind would be fool hardy.
You may find a logger or provider that will set aside the small amount of logs that you require, but unless he's a bud, you will be paying well above market to get them. It's usually just not worth the time or bother. Our woods crew would not do it.