Sounds pricey to me for such low season. I take it thats flying scheduled direct with Virgin or BA?? Which hotel?
£550 each for Jan, staying on I-Drive doesnt sound like a bargain, but OK I guess for Scheduled flights and a GOOD hotel.
You can probably do tons better using a charter. I wouldnt pay more than £400 each and that would have to be a good hotel!! Personally speaking, Id still shop around a bit more. At that time of year, there are bargains aplenty to be had.