We are in the same boat…
Verizon wireless is like $30 a month for broadband with a 250meg limit (IIRC) and $70 a month with a 5gb limit (weaksauce).
I’d like to find some more details on Sprint and/or personal experiences.
Oh and you can share the internet connection, looking into network bridging and if that doesnt work check out a program called ezproxy.