If the car is still slightly drivable I'd get a second opinion before abandoning it.

I've had engines replaced twice, in 2 different vehicles. The first one worked out very well, the second one blew the head gasket after 2 years. Still, if done by a reliable mechanic, an engine replacement can be much more cost-effective than buying a whole other car, if the car in question still has good tires, brakes, etc.

Good luck!