Check the crankcase pressure by putting a latex glove over the oil fill hole. If the pressure is positive, it is time to clean the PCV and check the vacuum lines for it.

Stalling is usually caused by a too rich running condition, easily checked by looking at the spark plugs. Running rich is caused by unmetered air getting into the intake manifold, reduced vacuum tells the engine computer to increase injector flow. To say nothing about the front O2 sensor sensing a lean condition and also increasing injector flow.

Of course, sudden stalls can also be an electrical issue. The engine torques too much, pulling on a ground wire or loose coil wire...
--
Keeping it running is better than buying new