You might be able to get master resell ebooks cheaper than plr ebooks,
but just think of how much money you could be losing by not being able
to edit the ebook. With plr ebooks you can edit and also add in your
own content, therefore that means that you can add in your own product
links and/or affiliate links.
If you were to sell an ebook that you just had normal resell rights
to, then who knows how many affiliate links are in that ebook from the
writer. You will have no control over their links, they could be
making a lot of money from your promotion of that ebook.
So make sure that when you purchase ebooks to sell, that you get
yourself the best plr ebooks that you can.
This plr ebook news story is taken from;
http://www.joel-osborne.com/news/Go-With-PLR-eBooks-Not-Just-Master-Right-eBooks.htm