Up here, the only Manns available retail or online are for the German makes, and, ironically, they're cheaper than any other filter for any other application on the market. The one that fits the Audi I used to have is under $5 whether online or at Partsource. Getting something for the G at the price requires me to go online, and for the F-150, my best deal is the Wix 51515 from a local retailer at $4.99.
The only place I've found Mann for domestic stuff is from the States.