I bought mine in Feb, when gas prices were slowly going up. I was expecting them to go much higher. When I bought my car gas was going for about $1.89/gal, today it's $2.27.
I bought mine because I do a lot of miles a minimum of 100 miles per day (sometimes closer to 200). With gas prices the way they've been it made sense.
I know for most people the "premium" paid for a hybrid isn't worth the savings in gas, but in my case the math worked out. I was getting 18 MPG in my old vehicle and now I'm getting 46.
So at that rate I was spending $4861.80 on gas in my old car and now I'll be spending $1620.60, on gas at $2.23/gal. So my Prius is saving me over $3000 a year, so that will more than make up for the $3000 more I paid for my Prius over a similar car. And actually for this purpose I'm comparing the Prius @ $20,000 to an equipped Corolla @ $17,000, however I do think the Prius is more actually more comparable to a Camry, Accord or other Mid-Sized car which would make it even closer in price.
Although I would not have been able to afford a $20,000 car if it did not get the mileage the Prius does.