The rate of a $100 Google Play gift card can vary depending on several factors. One of the main aspects is the current market conditions. In some cases, you might be able to find a relatively stable rate if the demand and supply for such gift cards are in equilibrium.

However, it's important to note that rates can fluctuate. Sometimes, due to increased popularity or limited availability, the price of a $100 Google Play gift card could go up. This might be because more people are looking to purchase these cards for various reasons, such as buying apps, games, or other digital content on the Google Play store.
Conversely, if there are abundant supplies or a decrease in demand, the rate could potentially come down. To get the most accurate rate of a $100 Google Play gift card today, it's advisable to check multiple sources, including online marketplaces that deal with gift cards. By doing so, you can compare the prices offered and make an informed decision based on the prevailing rates in the market.