Actually u can just do a simply calculation using ur wattage x ur qty x tariff...
Of coz by right, it will be 12x times electricity consumption of a single 10 watt light.

Btw, try this TNBES Calculator, just simply key in ur usage and ur expected total wattage into any column

Actually ur pendent light is mainly for decorative + feeling effect?
Or really using it to brighten up ur area?

If is deco, just get the lowest watt.
If brighten... actually since its a screw bulbs, u not needed to worry too much, i suppose the pendent light will originally come with some bulbs, use it to test, then go MR DIY (example) and get ur suitable wattage bulbs later on (less than RM5 per bulb, of coz can't compare quality with those branded bulb, but at least can have a test)

Ur choice of screw bulbs really save a lot of headaches, compare to those lights with own customized LED/length