you can buy them from NTUC or those photo developing shops
price range from $5.50-7.50
if you use alot of this batt, suggest you buy rechargeable CR123. seem before sim lim tower got sell the batt but I dont seems to see the charger. if you want can try to buy from oversea (HK) I got some rechargeable CR123 and charger from this site (www.dealextreme.com)
ooh forgot to add, FYI the website you can get a pair of rechargeable at less than $7.50SGD and the charger from $10-18SGD, all after conversion from USD. only issue is the wait from the item to be posted over
I use these batt for my torch, always get it from PhotoHut, its a kodak express outlet @ Sunset Way. price should be abt $6. i saw same batt @ NTUC going at $7.50 and $8.50 @ 7"11 stores.
I used tons of this bttery on my flashlights. If you get the rechargeables, be carefull sine mot of them are not 3V but 3,7V - I blew a USD15 bulb to find that out.
If you want to get the single used, Mustaff center sells a pair of the energizer e2 CR123 for for 6.50.