I am a MSPA Gold Certified Mystery Shopper. You will need to sign up with 100's of companies to get a shot at whatever jobs are in your area. All companies are different. Most companies will reimburse you for a certain amount of the food ordered, if you stay in their guidelines, if you order more, it is your dime. A few companies will give you a fee on top of the food reimbursement. You will have to do a lot of shops to make good money at it. You will spend lots of time searching the web for jobs, and arranging jobs in the same area, so you aren't driving all over the place and spending gas money. You will be spending lots of time writing reports. When you average out the money/hour, and factor in searching for jobs, and traveling tothe job, and back, and writing and entering the report, the job will then not pay much.
To get all the info you want on Mystery Shopping, go to
www.volition.com.
Good Luck.