When your vehicles ignition switch goes bad or is starting to go bad and needs replaced your car may start fine and then stall right after or the key may not go into the ignition switch as smoothly as before or the ignition switch will get hard to turn when you insert the key into the ignition switch.
If you can change the ignition switch yourself you could likely change it out for as little as $20.00 to $50.00 depending on the vehicle but if you need a shop to replace the ignition switch it can cost from $175.00 to $260.00 to replace the ignition switch in your vehicle.