Yes, texts to the USA are chargeable at 65p each, as per here.
But they don't have to be that expensive.
International calls & texts to overseas nos. from UK can be rather expensive but EE has a free add-on that anyone, on PAYG or contract, can apply for to give these calls & texts at a fraction of the standard rates. See The Free CALL ABROAD Add-on for Cheap Calls/Texts from UK .
But where are you now? Are you in UK or are you in US from UK?