Gasoline prices are regulated in New Brunswick, Prince Edward Island, Nova Scotia and Newfoundland and Labrador.
Right now, you want "Public Utilities Board" or
http://www.pub.nf.ca/ppoprices.htm. Then click on Motor Fuel for table of prices in various locations.
Check all of those provinces regularly. One week NB will be less, the next PEI, or NS. It varies, but a few cents higher per litre with a big rig is $$$$$.............. So, check.
:C