I have been posting on other sites, trying to get a feel for the "laws of supply & demand" . So all you 'cookers', chime in please!

Ok, I have been monitoring and reading dozens of sites with the "how to" and "I made this" and all that jazz. Now I have to say that I have had more than a passing interest in Bio for a very long number of years, because I am frugal (can you spell cheap) and not "green". That said, I will build a unit - Appleseed, Pearseed, Grapeseed, I don't care what its called, so long as it does the job. BUT, specifically, how much time or difficulty is there in gathering sufficient quantity of WVO, VO, etc., to make a tankful of BIO every week or two? Most of the fast food restuarants seem to have commercial outfits collecting for them (at the resturant's cost), here in the Phoenix Valley. The commercial tanks are nicely made and therefore easy to empty and maintain. How do you BIO-dudes setup to have collections at the particular sites? Or do you just go in and say "I can save you money, just give me your oil."??? And by the same token, how much do you get from, say, your average McDonalds or Jiffy Burger?