[fjtorres]

I'd say that price sensitivity is a consumer issue not a publishing issue per se.
Some people are definitely price sensitive and will not buy any book beyond their price range. Some are somewhat sensitive and others are totally insensitive to price. (Duh, right?)

When you look at book sales volume you're looking at an aggregation of all of the above customer types so just picking out one book or one author isn't likely to tell us much about overall market behavior because there are factors other than price that impact sales volume. Even focusing on one publisher alone won't necessarily give an accurate representation of the overall market, even for a single genre.

Anecdotal evidence is of little use as a single author with a strong following would be more likely to see little sales variance with price while a group of newcomers with no track record would be more likely to show significant variance.
Going high and staying high is definitely the right thing for J.K. Rowling, Nora Roberts, and other established writers with a track record. No risk there.
Joe Wannabe with his first book coming out of nowhere, no matter how good his cover, blurb, and sample chapters is going to be running a bigger risk going high, regardless of how good and well-reviewed the product.

But to extract meaningful price data you can use to assess how much extra risk Mr. Wannabe is running, you really need a big enough catalog sampling to get the non-pricing factors (like branding, author reputation, genre expectations) to cancel out.

And that is something only the big retailers can really do.
Smashwords data is useful as far as a trend indicator but it is skewed by their business model and I'd be leery to bet the farm on their sales ratios and sweet spot.

Three other pricing data points I'd keep in mind before betting the farm on $2.99 is that:
1- the aggregate average ebook price at Amazon is $6.87 (and Amazon's own ebooks run $6.99). Of course, that includes the price-fix BPH titles providing a pricing umbrella for their competitors. That average might drop if the BPH titles are allowed to float.

2- BAEN single title price has long been $6 and their bundled price runs $4.50 these days. (At least 4 new titles in each monthly bundle.)

3- Harlequin ebooks generally run $4.99.

My gut feeling is that the safe zone for a new writer lies somewhere in the $2.99-4.99 range depending on genre, rather than $9.99.