Theres no need for 5 randoms as far as I know, if the first random isn't hit then might as well just end the script.
[@main]
#SAY
Sup, wanna gamble, it will cost 10k.\ \
<Ok, why not/@nxt>
[@next]
#IF
CHECKGOLD 10000
#ELSESAY
You haven't got the gold to gamble!?
#ACT
take gold 10000
goto...