How much would it cost to travel America?

If you drive, you should expect to spend at least £100 per day. As you see, car rental is expensive, and even the cheapest hotels are £30. Driving cross-country is really a great way to see the US and really appreciate its natural beauty and vastness, and to see a lot of the country between the major tourist sites on the coasts, but as you see it is fairly expensive. You could do it for £4000 for one month if you stay in motels instead of B&Bs.

Flying is another option if you mainly want to see major cities. You would need to rent a car in some places, but at least some major cities could be seen without a car (Boston, New York, Philadelphia, Washington, Miami, New Orleans, and San Francisco). Most other cities have terrible public transportation, so you would need to rent a car at least for that part of your trip. And of course you would need a car to see national parks or parts of the US countryside.

Trains between cities are usually slow and expensive, but the Boston-New York-Philadelphia-Washington train is fast and can be reasonably priced if you book in advance.

They have some "Visit USA" airpass deals that can be very good deals. You usually have to get them with the same airline that you got your ticket from the UK to the US from, and they let you get additional flights around the US for a very good price.

The airlines Southwest, Jet Blue, and Virgin America can have very good fares, but they aren't quite as cheap as Ryanair.

Can rental is not so expensive. You can try to search and compare car rental companies online? RentaCarIn.Us provides a lot of cheap rent a car deals from major companies with unlimited mileage terms which a perfect for traveling across USA.

You need to be 25 to rent a car here. B&B can be very expensive. Do not assume they are cheaper than hotels. You need to have a credit card in your name to check into any hotel.

You can go on airline web site to see costs for domestic flights.