It's true we can't live on pork rinds alone but something like 30% of body mass is collagen (made of glycine) so gelatin snacks will always find a good home.
Protein costs are a pain but a true amino shortfall is rare outside the third world. I save cash by watching sales for stew cuts, ground, heart, liver, canned seafood, eggs, and dairy (even during strength training we don't really need hundreds and hundreds of grams).
Lots of: urban hiking, cycling, sprinting
Lots of: fresh meat, seafood, eggs, organs, tubers, starch fruits, vegetables, meat fat, dairy fat, oil fruits
Some: cured meat, dairy protein, sweet fruits, rice, pulses, tree nuts, oil seeds
Minimal: soy, refined proteins, sugar, liquid carbohydrate, grains, refined oils, peanuts