You can get a properly designed gasoline tank. There's a limit on how big it is before you become hazmat.My local mechanic charged $100 for the RAM ecodiesel oil changes. However, it took 11 quarts of oil vs. your Duramax's 7. He charges $35 for oil/filter in the hemi and it takes 7.
I like the transfer tank idea. Just curious, why can't you do that with gas? Static risk or something?
I forgot to mention that you don't have the PIA of gassers gelling up in the cold either. I had a factory block heater on my RAM and never had any problems. However, my brother's '06 Duramax has gelled up on him several times. So if you live in colder climates you have to add in the cost of running fuel treatment in your diesel motors too.
Here it's 118 gallons. Do not use a tank(or pump if appropriate) designed for diesel.
You'll notice the gasoline tanks and pumps are 4x or so the price of diesel.