Are you saying a business doing several hundre thousand to millions of dollers per year can not afford to pay a 30,000 bill for a tanker of fuel?  Even if financed for a year that is $200 interest, turn the fuel once per month and interest is less than 0.67 cents per gallon, the remainder should cashflow (i.e. sell $30,000 in fuel then order another $30,000 to replace it with the cash from the sales. then use the profits to reduce tje operating line for the initial fill.)