I checked the Cub Cadet web site and don't see a 44 inch model. It looks like they discontinued it; only 48 and 54 inch models are currently listed on their site. But I did a search on the 44 and found a page for that too, presumably an older one. It lists the Engine on the 44 as being a 20 HP though, not a 22HP.
Based on the MSRP and the sale prices listed, the price you were quoted appears to be a bargain regardless.
Here are links to both pages.