Ben Thanh Market is a tourist market now, i wouldn;t advise you
to go there to find cheap bargains because you will still get
ripped off anyway, even if you dun buy it, the store keepers still
have lots of korean and japanese tourist who will buy, i suggest an
alternative An Dong market in Chinatown area, less glamorous, but
still its way more cheaper than Ben Thanh market in the central
city.
if its only 4 days duration in Vietnam, just stick to
HCM-Cuchi-Mytho tour, you won;t have timeto go to Hanoi at all, oh
yea.. ignore what other threadsters here who think gals are cheap
in vietnam..if anything else, its way more expensive 
if you are looking for some nightspots, i can recommend you one or
two 
