SLS is a cut-throat place for most retailers. guess most of us will be familar with the old days of late 80s to 90s b4 the advent of posting prices online. all u need is one shop to cut prices b4 all the rest do so. and it can happen throughout the day. so, ur hdd may cost differently if u bought it in the morning, compared to nite.
anyway, the few more established shops in SLS are places like fuwell, cybermind, skysys (i think dats how to spell it). at least we are pretty sure they won't pull plug overnite... try to avoid all the shops at the 'back alleys' (e.g. costronic etc). these shops are runned by very very unscrupulous retailers. they are the ones who give SLS a bad rep by changing shop names frequently.