Industry standard is 5gb bucket for $59.99 - VZW is no more expensive than Sprint or ATT for WWAN data from a nationwide carrier.
The MiFi has almost all the functionality of a WiFi NAT router (except for arbitrary port forwarding). It supports up to WPA2, has MAC filtering, and DOESN'T require running a laptop to host the WiFi connection - which is why it's better than using ICS to share the aircard. And it's the same monthly rate as the aircard, and not teribly pricy.
FWIW you can get daily access for $15/day - if you only need occasional access it might be cheaper overall than a 2-year contract. Requires you pay full-freight for the device though since you won't get the subsidised price w/o a contract.