if it's really only about the traffic, and you don't have the option of connecting your Tablet via a cheap WLAN to the internet, may i suggest you use USB Networking.

this way you can use your computer's internet connection without having to use additional hardware for WLAN etc.

edit:
although you might have to install rootsh over your expensive connection first, because you need it to activate usb networking. but that's only a small package and doesn't have any dependencies, so it shouldn't be too bad...