The adult, one-way fare from Heathrow Airport to Truro, Cornwall via London Paddington on the train is about £30.
It depends where in Cornwall you're going. From Heathrow to Lands End is close to 250 miles.
Parking a car in Heathrow can cost different prices, depending where and for how long one parks their car. On average, parking a car in Heathrow will cost around 20 pounds.
About £70
The easiest way to get to Cornwall from Heathrow Airport is to take the westbound M4 motorway all the way until Bristol, then take the M5 motorway down to Exeter. From there take the A30 westbound until you reach Launceston, then you are in Cornwall.
£3
About £50 but check with the driver first.
There is no easy way of getting from Heathrow to Croydon. A cab would cost about £50
Parking a car for about a week at the Heathrow Airport will cost about 300 dollars. They charge about 50 dollars a day, but it is possible to get a long term deal.
About 65 GBP.
Take the M4 motorway until you reach Bristol, then take the M5 southwest until you get to Exeter, finally take the A30 from Exeter until you reach Launceston - then you're in Cornwall.
The cost of renting a room at the Comfort Hotel in Heathrow would be 49 pounds per night. It also depending on the day of the week, week day probably would be cheaper.
A flight from Heathrow to Miami will fly southwest out of London and then fly towards Devon and Cornwall before leaving UK airspace, then the flight will fly over much of the Atlantic before reaching Florida.