Instructions

There are two periods, you can buy one item in each period from a robot seller.
Originally your account has 100 points. Your total points increase by the value of the item if you get it.
Your total points decrease when you pay some points to the seller.

Basic information

At the beginning of the each period, both you and the robot seller know the possible outcome of your value.
Robot seller will set a secret price based on the possible outcome for each period.
Secret price in period 1 might be different from secret price in period 2.
The cost of producing the item for the seller is zero.

But only you know your true value when you enter the market.
You have to make a bid in each period if you are in the market.

In the first period

You have 50% chance to be the lucky buyer, who can get the item for free.
Otherwise, you can get the item only if your bid is not less than the secret price.
You only have to pay the secret price.

In the second period

Robot seller will set a membership fee based on your bid in the first period.
Only when you pay the membership fee can you know your value in the second period.
He will set another secret price.

You have 50% chance to be the lucky buyer, who can redeem the membership fee.
Otherwise, you can get the item only if your bid is not less than the secret price.
You only have to pay the secret price.