The rate of a 100-dollar Play Store gift card can vary depending on several factors. One of the main aspects is the current market demand and supply dynamics. If there is a high demand for these gift cards, perhaps due to the popularity of various apps and games available on the Play Store, the rate might be affected.

Today, economic conditions also play a role. Fluctuations in currency values and overall economic stability can impact the rate at which these gift cards are traded. For example, if there is inflation or instability in the currency used for the gift card transactions, it could lead to changes in the rate.
Moreover, different platforms and channels through which the gift cards are being sold or exchanged can have their own pricing strategies. Some might offer better rates compared to others. It's important for consumers to do their research and compare the rates offered by different sources to get the best deal for their 100-dollar Play Store gift card today.