Does everyone who wants that have one on their own server?
Some people turn to cloud storage services like Amazon, Google Drive or whatever else they want to use. How many bitcoins or how much fiat would people who want a full node pay for one?
A cloud storage service or any other service offering to run nodes for people is a third party, and anyone wanting to run nodes with those groups would have to trust that the service is abiding by the consensus rules in the same way that other wallets have to trust that full nodes are abiding by consensus rules.I'm sure that there are people who would pay for such a service, but the amount that you would charge should be less than the value of the user putting in effort for setting up the node themselves. You would also have to offer a lot of options for customisation of what the user wants (such as following a certain fork).