For marina fuel, Cap Sante has been about the lowest for diesel. They discount for volume.
Current Fuel Prices are on the Port of Anacortes web site:
If you can take 750 gal, it $2.07 US. . . .
I think you're thinking of Reisner Distributing. They have a permit to deliver to Cap Sante commercial pier. I used to use them, but with the price down now, it was hardly worth the trouble. You might save a few cents per gallon over the Port price.
This is their web site below:
Reisner Distributor Marine Fueling - Reisner Distributor
Reisner's minimum used to be 200 gal, but check with them first. They are one of the larger distributors in the area.