U can try get from East Gear at Pennisular Plaza.
I bought mine from there at $24.95 for my IXUS 400 also.
Pretty reliable and good...usage time last longer than the canon one cos this is 1000mAh instead. Comes with 6 months 1 to 1 exchange warranty.
Can refer to East Gear webbie here for more info.
http://www.massorder.com/shop/produ...id=98&osCsid=1c0ce47f3517a5917d3d40c256f37606
Good luck!