e-booksE-books seem to be costing consumers less money.

Digital Book World tracks the prices of e-books on the best-sellers lists every week. Last week, the news site found e-books on the lists averaged more than $8 a book.

After a week where a new publisher (Macmillan) allowed discounted prices, the average price of e-books on the best-sellers list dropped to $7.21, a record low, according to DBW.

One of the more interesting notes from DBW’s research is that $9.99 doesn’t seem to be a popular price anymore. This price point has been reserved for newer popular books and those that retailers can definitely move at that price.

Just two publishers, Random House and Penguin, have yet to discount titles. Eventually, these companies will follow suit as they have to discount based on the Department of Justice price-fixing case.

The falling price of e-books is good news for consumers. Less expensive books means saving money. Publishers and retailers may not be happy with the prices falling, but that quantity of books sold would be a good indicator if the price drop is working.

If readers are saving money on books, they could be more inclined to buy more books. Often, readers have lamented the price of e-books being cost prohibitive. Buying an e-book that costs $12, $13 or $15 simply doesn’t sit well with many readers, quite possibly because purchasing an e-book still feels different than owning a physical book.

Interestingly, the highest priced books on the best-sellers list all come from Penguin and Random House (one from Hachette). On best-sellers priced below $7.99, Penguin shows up on the list once.

It’ll be interesting to see how the price of e-books stabilize once all the publishers are offering discounted prices.