You can download as much as you can, there used to be extra charges the first time they implement the service and that was going beyond one 1 GB I guess ...

The sad thing is, when you open a new webpage these files are saved as a temporary files and will occupy disk space. Even those are counted, so every time you browse the counter would be working ...

But now no more, it is open like the sea ... ride your boat and catch as much fish as you want ...