Would love to hear the answer as I am having a similar situation with a company in Canada.

If it shows a B, it is already assigned. Nothing to do with the Shopper 101 test. Passing it won't magically erase that B.

They have been bought in the last year and some things have gotten "odd" since then.

One thing about them -- they start shops at fire sale prices -- $3 and $4 shops are common the beginning of the month or quarter. Some people (mostly newbies) will snap them up at that price. The ones that are not in shopper-saturated areas will go up at the end of the month, quarter, or whatever cycle the shops are on. Shops that offer $3 for the ice cream shops at the beginning of the cycle could be up to $15, $20, or even $30 depending on location by the end of the cycle.

Go ahead and take one for $3 or $4 if you want the food anyway; odds are you won't do that more than once. But it will let you know how much time it takes to do it and the report and then you can decide what your threshold will be. The grocery store up here starts at $4 and I won't touch it for less than $20. Seven interactions all with timings, names, and descriptions for $4 and a $9 reimbursement? Sorry, no. That's 7 mystery shops as far as I'm concerned. I'm usually in the store for 45 minutes to an hour and the report is a half hour to 45 minutes at least, not counting prep time, drive time, and search time to find the job in the first place.

So you need to find out for yourself what a shop is worth to you. Just know that they will go up if nobody grabs them for crumbs. Wait it out and see what they get up to before they're taken in your area.

Oh, the other thing about them is they pay quickly. But they are also unforgiving of any missed requirements, such as not getting a receipt or a required photo, or missing a deadline. If you're going to do them, do them correctly and on time and report in the stated window, which is not generous.