In addition to the market fluctuations, each city has different amounts of variability in resale value. For example, in one city, pairs of found items can be sold for $0.50 on average at one time, which, in practice, will mean that you would find one pair that is worth $0.60 and another worth $0.40. In the other city, where there is greater resale variability, an average value of $0.50 could lead to pairs of items that are worth $0.30 and $0.70.

These levels of resale variability within one city do not change over the course of the whole experiment. So when you revisit that city, you will have a sense of how much item values may fluctuate around the mean market value. However, keep in mind that the market itself also changes once in a while in average resale value of items, leading to higher gains at some points and lower gains at others.

To recapitulate, the order of the first task is as follows: (1) you will first see one of the two items you have found, (2) you will (quickly) give an estimate of how much items are worth on average at the time, and after submitting your answer, (3) you will see how much the pair is actually worth along with the second item belonging to the pair.