I think the secret to doing these big box store audits is to know which one you're going to be auditing, and how well the store is stocked, signed, priced and merchandised. Auditing he stores with minimal/no errors is not bad, even with reporting time.
God help you if the store you're going to audit is a mess. I did a series of audits for a location that was an absolutl cluster, and wound up taking pictures of the entire department(s) I audited for functionality - more than 50% of the displays were missing and or non-functional. Sales associates indicated that it had been that way for a looooooong time. I think I made $3 an hour on those audits, after it was all said and done.
I don't know if this particular big box store is stingy with the payments for these audits, or if it's Bestmark. Regardless, I wouldn't take a location that I knew was a mess, or an unknown location, unless bonused.