Here in Brazil is usually expensive to buy these batteries CR2032, used for computers, watches and other. In China each card with 5 costs less than $ 2, including the freight.
Apparently the quality is good: all comes without any damage or oxidation.
Sometimes you need one of these batteries to put in a computer and end up paying 5 to 10 real street vendor.
Worth it to buy this type of battery in China. The DealExtreme has a lot of different types of button-type battery for clock. I leave the link to some of them:
CR2032 – http://dx.com/p/cr2032-3v-lithium-cell-button-battery-5-pack-34712
Cr1220 – http://dx.com/p/individually-packed-cr1220-cell-batteries-5-pack-2893
Ag13/LR44 – http://dx.com/p/ag13-1-55v-alkaline-cell-button-battery-20-pack-52770-pieces
CR2025 – http://dx.com/p/cr2025-3v-lithium-cell-button-battery-5-piece pack-144,803
AG1 – http://dx.com/p/ag1-364a-1 .55v-cell--button-batteries-10 pack-2910
AG8 – http://dx.com/p/ag8-391a-1 .55v-cell--button-batteries-10 pack-3018
Cr2016 – http://dx.com/p/cr2016-3v-lithium-cell-button-battery-5-pack-34714