When posting prices please post the credit price rather than the cash price to keep things fair for all staations in the area. According to the site guidelines in the FAQ section:
Q: Do I post the cash price, or the credit price?
A: Most consumers use debit or credit cards when making purchases. We've had far too many complaints from people stating they've gone to a station only to find out they had to pay more than what was quoted on our site. That said, please post the price before the cash discount when possible. You can still provide the cash discount information, but please enter that information in the Comments field.

However, if the station does not accept credit cards and ONLY has a cash price - or the cash price is the ONLY price listed on the sign - please post that price but make sure you add a note stating "cash only" or "credit cards not accepted", in the Comments field.