Looks like your best bet is
Books On Board where the price is $9.98.
Fictionwise has a high discount on all their books right now but it's in the form of a micropay rebate, meaning you have to use the money you save at Fictionwise. So you actually pay $17.99 without a club membership but you get $10.79 added to your account. This is only useful for you if you want to continue to strip DRM off your ebooks (which I always do). There is a way to remove DRM from Mobipocket files but if you're not comfortable with the command prompt, I'd recommend you get the Adobe EPUB file because it will probably be easier for you to strip the DRM. Then you can use Calibre to convert it to Mobipocket (EPUB files convert very nicely to Mobipocket, so don't worry about that).
One last thing: EPUB files from Barnes & Noble have not been cracked, yet. They use a different type of DRM that will need to be cracked before you can remove it. So you'll want to stay away from them for now.
Hope it works out for you!