Hi Storeshopp,
Welcome to the Forum! Whether or not this turns out to be something for you, I know you have found a terrific place to research mystery shopping. If you ask questions in threads or search the existing posts in the New Members section or elsewhere, you can find a wealth of information on the topic of mystery shopping.
Regarding your questions, I think the most important things to say, even to repeat the excellent posts above, are 1) you are running your own business as an independent contractor for a large number of mystery shopping companies, 2) payments come out of your pocket and fees and reimbursements come from successful shops in the manners described above, 3) reselling isn't a big concern for many shoppers because we often choose shops that give us something we need or want such as groceries, coffee, gas, and restaurant meals (Try to resell the last one
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).
As to whether this is a good fit for you, I submit the only way you will know is after doing a few shops. Only the actual experience of making defined observations and reporting your results will tell you if you have the skills, mindset and perseverance to go through with this. So, read enough to learn how to sign up for companies, get the shops, avoid the scams and then go do some shops.
Good luck and have fun!
Happily shopping Rhode Island and nearby Massachusetts and Connecticut