3G broadband card for main internet

[Banzai_Joe]

Guys in the know,

our business HQ is at the very end of a BT exchange and as such we can only get 512Kbps, yes read it again 512Kbps adsl connection!!! Already contended it then has to be shareed between 50 users in the building.
Its download speeds are intermittent and range from 60KB/s down to 3KB/s (the lower speeds are more common).
Its THAT bad.
Now, the boss won't pay for leased line as its still quite a lot of money for in his eyes very little return (no matter how many positives i give him, he just doesn't understand )

Our laptop users when in the field connect to the internet and into our server via vodafone 3G usb modems currently as 3.2Mbps. We are due for upgrades to 7.2Mbps in the next month.

Now, after all that flannel, i theorised about using one of thess usb modem running at 7.2Mbps as an 'alternative test' for our main business internet access.
Can anyone see any logic with this theory bearing in mind:
Vodafone probably don't supply static IP's with these things (our sp is checking this for me).
It would be over 10x the speed we currently have.
There is a mast very close by so we should always get a good signal for max. speed.
We used to have Wireless SDSL (old tele2 stuff) but that was pretty crap! so we changed to ADSL.

We operate a domain client/server environment with exchange 2003 (using our own smtp) and windows 2003 servers.

Any advice really appreciated, thanks.

 

[Sone]

all the 3g connections i have used do not give you a public ip address

Data costs could be prohibitively expensive, i would have thought a 2mbit leased line could be cheaper.

 

[Banzai_Joe]

Our cards cost £25/month with a 5gb data bundle. £12 per GB over the limit.
Yeah, its not really feasible, that was the first thing i thougt of, but still wondered if there was a way to do it.
Leased line 2mbit would cost approx. £4500 install and £450/month. Its hard to persuade the boss to part with 10x a month what he is paying now.

 

[dan653]

our business HQ is at the very end of a BT exchange and as such we can only get 512Kbps

is that adsl2/adsl max? (whatever its called, the 'upto 8meg' one) if so when this is the case, often conventional fixed rate adsl can give a faster speed but still only 2megs (220kBps down/30kBps up)