We are on a 3G mobile dongle, which isn't too bad (1 to 2 Mb/s and 15GB/mth for £18).
We recently looked into satellite packages, and though obviously expensive compared with BT, I didn't think the costs were TOO horrific. For example, a 10GB per month connection giving up to 22 Mb/s download and 6 upload now costs £29 per month plus £150 installation. It also gives unlimited downloads overnight, so if you can schedule updates etc, that saves some allowance.
All I'm saying is that prices have dropped considerably over the last 5 years, whilst performance has increased, so if you haven't checked recently, it might be worth revisiting.