There is a lot of good information in this thread. Pricing/market prices/quality etc is very important.

However the number one thing you need to get a good handle on is what is your cost per ton THIS year.  Once you know what your cost per ton is likely to be this year THEN you can look at market factors, quality, rfv, etc. And be fair to yourself on how you value your labor and return on machinery and any other owned assets you use. This is a fairly complex arrangement you have but really try to include all of your costs.

Once you know what your costs are you can get a handle on what your profit would be at various pricing levels. I would use the Penn State data so you have something in writing from a university to show your customer. Russ' post includes some numbers to compare. And you must price your work/product at a profit.

And in order to do that you need to know what your costs are. All the best.

Jim at Dawn