Unfortunately, it's easy to get stuck daydreaming and end up 10 years later with nothing to show for. Just start where you are. Buy a 5lb bag of flour and make VWG... compare weights from before and after.
Most good wheat is around 10%-14% protein. Vital wheat gluten is the protein. Depending on extraction methods, VWG is about 70-80% protein by weight, the rest being nutrients that aren't easy to remove.
Therefore, per pound of flour: (1lb flour * 0.14) * .75 = VWG/lb wheat ... So for 1lb of flour you're looking at a ~10% yield, or barely 45 grams of VWG. That is why the stuff is worth its weight in gold.
You're better of sticking to the grocery store or co-ops where people can produce things in bulk more easily for vegans, unless you're whole food vegan, in which you'd need to grow a lot of legumes if you want to
feed yourself and remain healthy. I am a vegan, but if I had a homestead, I would not be. Veganism is more suitable for those living in modern society. I do not believe it has a big place in the wild or on a homestead. For those of us estranged from our food sources, it is the best option, in my opinion.