The first sentence doesn't fit into the context, as my original "also" referred to a half-sentence on spreading costs in the previous sentence (written probably by Jérôme). I used 'extra cost' to denote price above market price, I'm not sure 'additional cost' covers that meaning. The 'guaranteed purchase at fixed higher prices' directly does the spreading of costs, "utilising the advantage of" just doesn't sound right.

_{*Lunatic*, n.
One whose delusions are out of fashion.}