I for one think it's a great idea! I would love to do something like that, but have nowhere near the capital or resources to even imagine doing something on a commercial scale (heck, I don't even have the facilities to brew my own!)...
I say, if you have the ability, go for it! BUT, keep in mind that you'll need to either grow or find a source of ****** oil. I don't think that bio-D made with waste oil will sell all that well, not to mention being more of a PITA to make on a large scale and finding enough sources of WVO to be able to produce on a commercial level...
There's a station locally that's finally selling B-99 at competitive levels with conventional diesel fuel, so it can be done...