You can't sell grass for that. we worked it out as costing £31 per acre for fertilizer.It will have an affect on the quality. But your question of what type of grass is perhaps better from that POV.
However I was also thinking how can anyone afford to sell fertilized grass for £20/acre?
You could sell it at so much a big bale. It will cost around £30 per acre to make if weather is good and £3 each bale. So ask £5 or 6 per bale and you might get 50 to 90 pounds depending on crop. Buyer will still be getting a bale for no more than £12.