[jbernsteiniv]

Non-dairy milks are about the same price as dairy milk where I live.

Tofu is pretty cheap (about $2.64 - $3 where I live). It is also very versatile.

Beans are very cheap whether dried or canned. You can usually get them for about $1 / lb and the price drops of course the larger the quantity you buy.

Oh and if you think beans are a good source of protein, why don't you talk to my friend: split peas.

The only example I can see you gave that would be expensive is the "processed capsule" for omega 3 supplements.