I worked at a gas station for a bit while in high school. Many gas stations price match with each other. My boss would record every other gas station's prices each morning and we would go one cent lower, as per company policy. While that was 10+ years ago now, I'm sure that they still follow this trend. While their stock is probably fresh, another gas station nearby might be trying to move some older, ethanol-free gas and lowered their price- causing those who price match to lower theirs as well.