I have a rental that is aluminum wiring. I’ve had the house for 8 years without any electrical problem.
Aluminum was pretty common in the early 70s. The problem with aluminum was that it expanded and contracted with the temperature changes of summer to winter, more-so than copper. Was blamed for some fires. However provided the house is wired correctly, it shouldn’t be a problem. Some people tighten their connections once/year or so to be safe.
Not sure if it would matter with your future buyers lender.