They claim they are paying the hazmat and building it into the price. How can you do that without knowing how many cans people are going to order?
Say everyone ordered 4 (optimistic). 4 x 27 = $108. minus 20 for hazmat and at least 5 for actual ship costs. Leaves $83 or just under 21/can - little room for any profit.
At 2 cans/order, they have 54 - 25 = 29 or 14.50/can - most likely a loss.
1 can is 27 - 25 = $2/can - big loss.

Having no minimum is either a very foolish business decision or something is not right.