In the era of 99 cent apps, GPS-based driving assistance for the iPhone has up to now been a big financial nut to crack, with apps regularly costing $70 or more. Navigon, makers of MobileNavigator, have addressed this by introducing Navigon MyRegion, a regionalized GPS navigation system priced regularly at $30, but available for a limited time for $25.

Sporting the same set of features in the “regular” version of MobileNavigator, MyRegion includes the entire U.S. map, with either western, eastern or central regions unlocked. You can unlock additional portions of the map for $13 (normally $15) as In-App Purchases. Traffic Live, which adds live traffic avoidance to MyRegion, is also available as an In-App Purchase, regularly priced at $25, but available until April 12 for $20.

MyRegion has been introduced specifically for the United States. The full version of MobileNavigator with map access for all of North America including the U.S. and Canada remains available in the App Store for $80. MobileNavigator is also available for other geographical regions.

Navigon notes that MyRegion will support MyRoutes, a new feature to be added to the 1.5 release of MobileNavigator this spring as a free update. MyRoutes provides customized route recommendations based on your driving style.