At first glance BajaLibros looks to be just another ebookstore that sells Epub. Like many others, they have apps for Android and iOS, both of which were developed by Bluefire.Their ebooks can be read on almost any ereader besides the Kindle, including Nook, Kobo, and others.
But BajaLibros does also offer their own ereader. The Papyre is a rebranded 6" ereader that I believe was originally developed by Quisda. Assuming the product page is accurate, it's being given away in Argentina with the purchase of an $800 store credit. I believe that price is in Argintine pesos, and is equal to about $155 USD.
If you're not up on the SA ebook scene then you might not have heard of BajaLibros. I had not, but I was told today that they are one of the major ebookstores in South America. They reportedly generate more sales for the Spanish-language ebook distributor Libranda than either Apple or Amazon. From what I have been told this would have been the ebookstore that Kobo or B&N would have approached if they were looking for a partner in the region.
This ebookstore currently boasts that it offers "more than 50,000 books, novels, and textbooks, including classics and bestsellers" It's not clear how many of those titles are offered in the US, but it does appear that BajaLibros is smaller than either the Kindle Store or the Nook Store.
I just checked, and the Kindle Store currently shows a stock count of 53 thousand Spanish language titles, easily matching Baja Libros' reported 50 thousand plus titles. The Nook Store has over 58 thousand Spanish language titles (according to the B&N website).
You can also find a limited selection of foreign language titles in BajaLibros, but I would not buy them. The English language content appears to be public domain titles which are being sold for $4 each.