Jim, I understand your frustration with your vehicle keys. However, you seem to be willing to "cut off your nose to spite your face" by abandoning your Prius, because you have misplaced your keys a few times.
My wife and I travel with our 2008 Tundra and Airstream travel trailer, which affords many opportunities for getting locked out. After several close calls, we have one simple rule when camping:
• Our two sets of Tundra and Airstream keys are either in the ignition- or door-lock, or in our pockets -- at all times!
While having small children can be a distraction, most Toyota owners do NOT have problems with getting locked out. Surely, with a little discipline, you can overcome this problem and avoid the unnecessary expenses associated with key replacement.
Please, don't take this as a personal attack or criticism. It's just difficult to understand how you are willing to abandon a perfectly good vehicle when the simple solution is to put your keys in your pocket.