oil leaks on 1996 Saturn SC2

My car is leaking oil from the valve cover gasket, oil pan gasket, and front crank seal, per a repair man. What should the cost of the repair be, bare minimum....and what is the amount of oil I should keep in it to keep it full?

1 answer
You should keep the oil at the full line on the dipstick to avoid additional damages. DO NOT over fill the oil.