Do you think reporting these requests to the store(s) in question might result in investigation, or at the least, a list of suspicious investors to use to vet extensions/apps?
1. What rules are being violated by these offers? It is what happens after the sale might break the rules but I can't report someone for having bad intentions.
2. I do not believe Google would be interested in spending even a minute of their precious human time to do any real investigation. If they can't automate the solution then they ignore the problem.
They might be people who were already banned for modifying other extensions into malware, back at it again on a new account. The hint that they're trying the same tactic might be enough to link their previous and new accounts, and then ban them again.