Do the people who sold you the ebooks hold the copyright on the books, or have a valid license to redistribute them if not? What does the MRR license give you?

Wikipedia has the following rather shaky info.: "When you acquire master resell rights, not only can you sell it to your customers, but your customers also have the rights to sell it. You can also sell master resell rights to your customers, so they too can sell resell and master resell rights." Sounds like a recipe for disaster, frankly, or at least for some variation on multi-level marketing, which is not a way to make money unless you are at the top of the food chain.

I've never heard that term before, and Wikipedia wasn't much use, but what matters isn't what the license is called, but what it grants you, and whether or not the people who sold you the license actually have the ability to do so. You sound like you have some doubts about this.

I am not a lawyer--but it seems to me that you have a couple of options. Either consult with a lawyer with experience in copyright law. That's the safest course. A riskier one is this: IF the MRR license clearly states that the person selling you the license grants you the right to do something, and if you can't find any evidence that they don't have the power to grant those rights, you can go ahead and sell it. If a copyright holder comes after you, tell them you bought the rights from so and so, and of course stop selling the book. You would be within your rights to be relying on their license, it seems to me.

But. I am not a lawyer. I am, however, a cautious person, and after looking at a few websites in the MRR area, I have to say I'd stay away from this. There's a lot of hype of the kind I see on sites pushing scams and near-scams. Whenever i see that kind of language, I stay away. Since you've already invested, proceed with great caution and don't invest any more money until you've talked to a lawyer.

it's unfortunate you didn't get advice before you made these purchases...

I have had a small amount of exposure to these e-books from the perspective of somebody whose content has been stolen and re-sold.

How these often work is that a person creates the e-book by stealing content from elsewhere and selling it with resale rights. He or she then claims that he is not the original creator of the e-book but has innocently purchased it (with resale rights) from another vendor (who he is now unable to contact). It is basically a method of attempting to avoid responsibility when selling stolen content.

I am not a lawyer so I can not give you advice on whether you have the legal right to re-sell the e-book which you have purchased. However, if it turns out that the content was originally stolen it is quite likely that the original author will discover versions of his work for sale without permission and request that the online shops selling this work (eg e-bay etc) immediately cease to do so and close down the account of the vendor.

If it turns out that you are re-selling stolen content then you should be be prepared to provide evidence that you have purchased it and valid contact details of the vendor. Otherwise you may be blamed for creating the e-book in the first place. (again, I'm not a lawyer so don't take this as legal advice).

Also, even if the content is not stolen, the business model sounds very much like a pyramid scheme (ie, buy a book for $x and then sell 100 copies for $x each, making loads on money in the process). Do you REALLY plan to make your fortune by participating in pyramid schemes? Do you REALLY want to spend good money on legal advice to support this "business venture"?