Gruyere is a hard yellow cheese found in Gruyeres, Switzerland. It is a firm and smooth Swiss cheese (without holes) and has a distinctive buttery, nutty, salty flavor. At the time of publication, the price of Gruyere ranged from $9 to $15 per pound, depending on the age of the cheese. Aged gruyere makes the flavor sharper and more complex (and more expensive). Several comparable less-expensive substitutions can be used without significantly compromising the quality and flavor of your dish.
Fontina cheese is also a cow's milk for the Alps. As of the date of this publication, it is more mild than Gruyere cheese and melts well. Fontina can be found for $5 per pound, but can get as expensive as $17 per pound.
Comte' or Compte
Comte' or Compte is a French cheese made from unpasteurized cow's milk. Comte also has a complex flavor and melts and shreds well. It costs about $15 to $22 per pound, as of the date of this publication, therefore the price is very comparable to Gruyere. However, Comte' is more readily available than Gruyere, and you may find a small piece for a deal in your local supermarket's specialty cheese case.
Jarlsberg is a cow's milk cheese originating in Norway. You can find it for as low as $5 per pound, as of the date of this publication. Although it is slightly more mild than Gruyere, it is a fine substitute, especially for any recipe that calls for melting the cheese into a larger casserole dish. Jalsberg blends and holds it's flavor well.
Appenzell is an aged Swiss cheese known for a distinctive spicy flavor that comes from a secret herbal brine used during production. As of the date of this publication, it can be found for as little as $9 per pound, and as much as $37 per pound. You can buy Appenzell in small quantities in many grocery specialty cheese sections. Keep a little on hand to mix with other cheeses like Jarlsberg to deepen the flavor of less-expensive and milder cheeses.