If you are using conventional oil or synthetic blends they will cost you less. They are less expensive and cost you under $20 for a 5 quarts bottle. For getting the same advantages as fully synthetic oil by spending less money, you should use synthetic blends.u003cbru003eHowever, fully synthetic motor oils are expensive. It will cost you over $20 for a 5 quarts bottle. The price may differ based on the quality of the oil. You may get this at a cheap rate ($25) or a high rate ($60).