I think that the cost is also related to the dose used. My body is small & thin; and I think that the doc said that each dose would be 2g/kg. I weigh 50kg/110 lbs, so each dose would be 100g.
There don't seem to be any price quotes per gram available, but I expect that because of my body size, the cost would be on the lower end of the estimated cost range.

Not knowing how many I may need to have is what I am concerned about.

With love, Erika