I am a recent Prius convert. We still have our tank of an SUV (need it for boat, etc) but this Prius is fun to drive and gets an amazing avg of 50 MPG. We did buy it new, but this is because after looking into used and finding a new one with the tax rebates, it just made more sense to buy new. Toyotas hold their value a little too well for someone to buy used when the rebates are still available (they will only be there until a certain amount of them are sold).
I have owned Civics before (back in the early to mid nineties) and I was worried that the Prius would feel like a Civic in terms of space, but it is actually much more roomy. Believe me, I was skeptical at first, because from the outside they looked so small.
Worth looking into!