Hamburger Helper sales rise as Americans try to stretch their food dollars:

[Buzz cook]

8. horse, goat, beeffallo, and buffalo

Were all alternative to beef in the 70's. Sadly they're all pricey now.
I don't remember mutton from back then. Maybe we'll see it now.
I've never cooked mutton, it looks like the least expensive. But a web search found only one seller.

"In 2025, the approximate wholesale price range for US goat meat is between US$ 6.09 and US$ 10.15 per kilogram or between US$ 2.76 and US$ 4.60 per pound(lb)."
"In 2025, the approximate wholesale price range for US horse meat is between US$ 1.36 and US$ 4.76 per kilogram or between US$ 0.62 and US$ 2.16 per pound(lb)."
https://www.selinawamucii.com/
"Ground Beefalo 1.5 & 2.5 LB Beefalo Chubs $7.99"
https://melloranch.com/meat-prices/
In 2025, the approximate wholesale price range for US mutton is between US$ 4.12 and US$ 6.17 per kilogram or between US$ 1.87 and US$ 2.80 per pound(lb).
https://www.selinawamucii.com/insights/prices/united-states-of-america/mutton/