Tortola is only 12 or 13 miles long - gas is more per gallon, your mpg will be low, but $300 seems too high, or is that for two cars? You wouldn't be carpooling to work?
Why have a landline if you have two cellphones? And it will take LIME months and months to install if you believe the chatter over on facebook BVI Community Board, so you can subtract out a few months!