RPI has a vendor that allows you to rent a MicroFridge for the year. When you move in it is already in your room and you can just leave it there when you move out. The cost of this is $220 per year.
You can buy a mini-fridge for anywhere from $100-150 dollars. You can buy a microwave for about $50.
If you buy a mini-fridge and a microwave separately, you still are under the cost for renting from RPI’s vendor. And you would save money in the long run because when you buy your own stuff you can keep it for more than a year. For that reason, I recommend buying your own mini-fridge and microwave instead of renting it.