I found a local butcher that has 17-21MM goat casings for $42 per Kilo. Thats 2.2046 pounds. So would that be considered a standard price? Looking on line they are sold many different ways and is hard to compare the prices.
Last time I bought sheep casings, there about the same as goat, I paid $9.99 for a 5 oz package.
Sheep casings are 20-22 mm and the 5 oz package will stuff aprox 15 lb of sausage.