+1 on a Ninja 250 (or a Suzuki TU-250, just in case you want Fuel Injection and like the look of a 60s Brit bike). But I will argue the cost for any motorcycle is about $1000 higher than the initial purchase price (because you'll want training, helmet, and a full set of quality all weather riding gear).
Still, $3000 and 70+ mpg, if your local environment allows for year round riding (with the right gear, year round riding means simply never have ice on the road, I ride quite comfortably at 5C).
If you don't like shifting (something 90% of the Canadian and American population seem allergic to), 125cc, 250cc, and 300cc scooters are really practical vehicles. They require a bit more confidence in your masculinity to drive, but if you are man enough to ride one, they get great fuel economy, provide a big built in storage area, and can take luggage like a motorcycle if you need more space.
Going back to cars, you mention two compact (what was 'midsized' 15 years ago) cars. What are you transporting that requires comfortable seating for four adults? What about something like an old Yaris (Hatch), xA, Versa (Hatch), or Fit? With nothing more than careful driving, all of those are good for 35+ mpg, all can be had 5 years old with a big chunk of the depreciation gone, and all are cheap to maintain. I think they even have more cargo space than the Prius.