Not a mod, but the Rabbot was a Darling Doorbuster Deal - it was released independently from the current sale.
For future notice, every Monday around 2 PM Eastern Time a single item will be listed in the market for a 'flash' sale. These are called Doorbuster sales and are only available on for 24 hours at most. Sorry that you missed your chance for the Rabbot but it's likely you'll see it offered again so I wouldn't fret too much.