Hi Cays
Rather than discuss S2 pricing, I've owned a KM Z5 & I own an S2.
The KM was appalling at focusing in low light, so much so it was unuseable indoors unless very (and i mean VERY) bright lighting was available. Even bought a camera-bright to see if it helped but just had photos of squinting people. I sold it on and changed it for the S2. Note the one excellent thing on the Z5 was the burst mode... awsome!
I can honestly say I've no issues with the S2. It takes supurb photos and excellent videos. Get some 2500 batteries and keep taking pics all day AND all night.
Hope this helps...
YT