eh.... let me do the calculation for you:
1 piece of EN-EL1 costs you S$65
3 pieces = S$195 oredi. Enough to buy a batt pack liao.
And hor this batt pack has few advantages:
i) provides more stable grip.
ii) vertical shutter button (not to mention the wide and tele button)
iii) adds the weight of the camera --> more balance and comfortable grip.
iv) uses 6 x AA batteries which can be easily replaced in future.
(EN-EL1 according to some ppl lasts about 2 or 3 years, that is the lifespan, does not depend on how you use it).
i rather that they don't provide charger and battery in the package rather an option to choose the batt pack by topping up:
2x ENEL1 = S$130
1x MH53 charger = S$30
Total around S$160 liao loh. top up S$20 more can get the batt pack liao which can let you shoot until ...... you

)