I found it cheaper to buy batteries from the dealer/distributor.
My favourite is the Bosch Dealer in (03-3341 0072) Jalan Kapar just before an Esso Station.
If you are from the Klang town center it is about 2~3 blocks down on your right, before that 'famous' rim shop.
Bought a Din 55 S3 Bosch MF battery at RM225 after trade in old battery at RM25 last month.
Bosch S5 MF Din 66 would be RM380 (S5 = premium spec, S3 = economic spec)
Bought NS70L at RM230 the year before.