I was looking for a one way rental EWR - NYC and the lowest rate I could find on US search engines was around 65-70 USD before taxes and fees for a midsize or fullsize car. I looked in dollar.co.uk and it gives me rates of around 30GBP (roughly 55 USD) inclusive of taxes, fees and all insurance (LDW, SLI and more). ^

The catch is that you must have a non-American drivers license and you must pre-pay and get a voucher but this is a great bargain!