Integrate Trust Deeds. In this case, I will not waste my time tuning the nodes and buying VPS is a waste of time and money. And I do not know if there will be a donkey that will launch its nodes at TestNet! But how will you test the TestNet platform with a small number of donkeys (if there are such donkeys) - that's another question.
The foundation will run testnet nodes but the public can also run testnet nodes and review the code. No block rewards or other payments for running a testnet node. It is voluntary.