Cheap egg substitute in baking

Soy flour and water! (That is, one tablespoon of soy flour and one
tablespoon of water. Use more flour if you want.)
But, do NOT use it in cookies - it won't work.
From October, 2023:
It's a good egg substitute in bread, muffins, pancakes, and maybe at
least a few cakes that call for three whole eggs at the most. (It USED
to be a lot cheaper than using eggs, but if it's becoming hard to find,
that could mean the price would go up too.)
I finally found a 1.87 lb. bag for $8.99 at a Japanese-Korean grocery
that's just  a 15-minute walk from my place.
I'll have to keep it in the freezer after I open it, since there's no
way I'm going to be baking enough times per week. But it's good to know
I can buy fewer eggs in general.
There were smaller bags of soybean POWDER next to it, but the price was
just over $7 a pound. Clearly not worth bothering with.
Soy flour weighs 142 grams per cup.
So that makes just under 6 cups per bag - or 95.648 eggs.
Or just under $1.13 for a dozen "eggs."
(Aside from cookies, which I already mentioned, one clearly would not
use this in, say, souffles!)
Also, I recently made brownie pudding with real eggs and it was a big
hit at my workplace, even though I accidentally put in too much cocoa,
but since the recipe calls for four eggs, I doubt it's a good idea to
use soy powder for that either! Just a warning.