To give my own experience, we bought a plug-in hybrid last year. It's a Chrysler Pacifica minivan. TBH, the thing is awesome. It has all the benefits of a minivan (it's huge, I can through both my kids bikes in the back without having to twist handle bars or remove tires, I can pack a week's worth of camping supplies + 4 people + a large dog + kayak + Paddle board etc..., not to mention the entertainment centre for the kids each with their own screen, power sliding doors with kids is amazing, etc...). The plug-in battery gives us about 60km of pure electric range, once that battery is dead it drives like a regular hybrid.
During the summer we pretty much only use the electric motors. 60km is more than enough for our daily routine of school drop off, work, kids activities. We really only use gas for road trips. Last year it averaged out to about 4.5L / 100km (~52 MPG). In the winter the engine comes on much more often just to heat up, we were around 8.5 L / 100 KM (~27 MPG) last winter. That's on par with our sedan, but with a 5,000 lb minivan. Overall pretty decent.
In terms of price, I don't think you end up ahead with a hybrid. The amount you save in gas over the lifetime of the car probably works out to be the same as the up front price difference at purchase. But it is a fun technology toy, and even accounting for the battery manufacturing and disposal process it's likely still better for the environment than a pure gas powered car.