It depends on how the legislation would be drafted to implement such a tax.
The difficulty comes from the fact that design greatly influences implementation. However, given that the number of platforms to which a tax of this nature applies is not very large, there is probably no need for hundreds of public servants to administer it. We just need to have the right legislative tools. I don't think this tax would require a lot of resources, given that the players to which it would apply are relatively few and easily identifiable.