Hi, welcome to BYC!
Wheat is OK as PART of the diet, your yolks won't be as yellow as if you feed corn.
But in NO WAY is it sufficient as a complete diet. First, it is too low in protein and chickens NEED the amino acids contained in animal protein to sustain them. 16% protein is the
minimum needed to sustain a light bodied layer like Leghorn. If I remember correctly, wheat is around 14% protein.
Second, it is lacking in vitamins and minerals which are ADDED to layer or any other formulated ration that IS meant to meet the nutritional needs of the animal.
I can get a lot of things cheaper than chicken feed... but I didn't get chickens to save $. I got them so I could get eggs from hens that were living a BETTER life than they would in the factory. And NO, I can't raise my chickens or get eggs cheaper. They cost me more because I can't get feed at the same price as the factory. They have means to store their grain and therefor save by buying tons at a time. While I can save some by buying larger amounts, I am limited on storage and then I have to worry about rodents, mold, grain mites, or other issues and might even lose what I have stored to those conditions.
Layer feed also has oyster shell, usually at a rate of about 4% which helps the hens to have solid egg shells. I personally don't use layer because I wan't my heavier breed birds to have a good amount of protein and NOT the bare minimum. I want them to thrive, not survive. I provide oyster shell free choice on the side and they use what they need.
If you feed wheat as a sole diet long term, eventually any saving you make will be defeated by decreased egg production (even if you don't notice you aren't realizing your FULL potential), and by diminished health of the flock. They will be more susceptible to illness and disease and they will die younger. Also, nutritional deficit leads to flock behavioral issues like feather picking. Feeding a nutritional balanced feed is the BEST thing you can do for you birds, aside from not overcrowding and making live in waste filled conditions. If you choose to feed only wheat, I would suggest finding a good vitamin and mineral supplement to add with it, which might negate your savings to.
IF I were gonna include wheat as a major component of the diet... I would definitely sprout it and/or grow it into fodder. That being said, my time is more valuable than gold. Once it's gone I can't get it back or make more of it. So it's not always about the mighty $. Life is too short.
If your birds are free range and the pasture is good with bugs and a variety of greens, you may be OK. But ultimately as a person who cares about helping people get the best and do the best for their birds... I would NOT feed wheat as a sole ration and I hope you don't either. I have felt that temptation before.