Hi everyone. I have a little hobby on the side which involves sewing  shiftboots and handbrake boots for cars. I have done a few vinyl pieces  for friends, but I am looking to step things up. I have gotten quite an  interest from many people for leather boots for their cars and I might  be able to make a very small profit on the side when I have time away  from school work. 
I would first like to ask what hide should I be looking into. Vinyl  seems good enough for most people when it comes to interior boots, but  many prefer leather due to the fact that it comforts them knowing they have a leather item. I have compared leather and vinyl boots with my  friends, and it is apparent that the difference when installed is  unnoticeable to majority of people. Because of this fact, I would like  to look into the cheapest hides available. This is where I start to  become confused because I do not know which hide is the cheapest. Pig,  cow, sheep, or lamb? 
Another obstacle I am facing is ordering hide. I do not know where to  order from for the best price (quality is not a major concern  here).  I have looked into Tandy leather, but I am looking for more  options. I am looking to make ~ 20 boots a week, and each boot would  require about 14x14 inches of leather. 
If anyone could help me out for my situation, it would be greatly appreciated. Thanks in advance!