Long story short.
I'm starting up a vpn and having mobile access from laptops on the field. Their laptops will have their own isp. I'm going cheap. Sprint's mobile offers the lowest. For 39.99 it allows 40MB of data transfer a month.

The laptops won't have web broswer access. Only the ability to connect to the vpn and view thew network.

The file in question the laptops will open is a replica of a file on the database roughly 80MB.

My mind is somewhat boggled and I cant think this one Through. Will the laptop do any kind of data transfer ( such as requiring 80mb of tansfer to open) or does it just use the remote connection to open the replica on the server side?

Rsync and deltacopy could be used to sync copies of the data.

Check in and check out may be an issue. Not sure how you use the data.

Remote desktop is about as small as it gets. You could easily go over that 40M each month.
The application and data would reside on the server. Might still have check in and check out issues unless the program is meant for that use. IBM products do well in that and some other top names.

I read it wrong and answer it wrong too. So get off my case you peanut.