You couldn't ask payout anytime as you want. You must accumulate your points to certain level and exchange for money in the cashtalk shop there. I think minimum cash out should be 100,000, so you still have to accumulates some points before you can request payout.
yes you are correct minimum exchange limit is 100,000, but we will be paid only $0.5 for so much points. That's why it is advisable to request payout after we reach 10,00,000 for which we get paid $15.