my opinion,
for my car, pumping full tank of Esso Ron97 is around RM140++. let say RM150.
if using Ron95 is around RM95++. let say RM100.
if using Ron95 + octane booster (RM20++ or more), let say RM100 + RM20 = RM120.
so save around RM50 per full tank. with octane booster, save RM30 per full tank.
Ron97 can go slightly more mileage n a lot better performance. Ron95 is a lot cheaper, Ron95 + octane booster is slightly cheaper & improve the 95 performance, but ppl say that 97 is cleaner than 95. for long term, i think should maintain with 97. short term, slightly saving money, then maintain with 95.
As for me, I'm using 95 for my daily drive to work. and sometimes with 97 during the weekends or bla bla bla...