I want to host 20 copies of the same VM for a final exam I am giving in a Computer Science class. The campus resources have proven extremely unreliable and I'm looking for alternative solutions. Ideas are:

* Host them on my home server and direct students there
* Go to some commercial cloud service

If I host them myself, is there a back-of-the-envelope way to see if my home server has sufficient resources to handle this?

If I host with some provider like AWS (or similar) is the cost manageable (ie, under $50 USD for 20 servers running for 8 hours)?

Are there other solutions I should be considering?