If you have multiple, unrelated projects, is it a good idea to put them in the same repository?
myRepo/projectA/trunk
myRepo/projectA/tags
myRepo/projectA/br
I would use multiple repositories. In addition to the user access issue, it also makes backup and restore easier. And if you find yourself in a position where somebody wants to pay you for your code (and its history), it's easier to give them just a repository dump.
I would suggest that consolidating repositories just because of the charging policies of your hosting provider is not a very good reason.