RESQUE is a predictive quantifier that estimates the retraining cost of a model to distributional shifts or change of tasks.It provides a concise index for estimating the resources required for retraining the model.Experiments demonstrate that RESQUE has a strong correlation with various retraining measures such as epochs, gradient norms, and parameter changes.RESQUE enables users to make informed decisions for cost-effective and sustainable retraining options, reducing the model's environmental footprint.