ispy, I am also mentioning this more for all new shoppers since you mentioned a shop that sounds like it is a high-paying shop. If this involves a check that they sent to you first for a shop to be completed (hasn't been done yet), it is most likely a scam. Run!!!!
A typical mystery shop involves you doing the work (the shop and the report), submitting the report, the MSC grading the report, then paying you between two weeks to three months later. Instead of relying upon offers sent to you unsolicited, please visit the Official List of Mystery Shopping companies at the bottom of this forum and sign up with these known legitimate companies.
Also, "scammer checks" can have a known legitimate company listed on it and that still does not guarantee that the check is real. Be sure to do the "Does this make business sense" test to yourself before getting yourself in trouble.
Shopping across Indiana but mostly around Indianapolis.