Essentially, the answer to this question requires some knowledge about the home. Since every home is so different (in size, age and in the improvements that have been made on it since it was initially constructed, to name but three important factors), the particular home’s specific issues would need to be defined first.
Be that as it may, a home that you are planning on selling in five years is still a place where you are going to be spending a great deal of the next half-decade.
But you’re not staying forever, so large capital improvements may be unwise. Air sealing is the least expensive home energy improvement, plus it generates the biggest bang for the buck. In any upgrade, it should be included.