As others have said, there's usually alot of hidden extras, but it certainly is cheaper to train in the US for the individual course price.
Im training modular and I trained for my PPL in the US. The price tag was very very cheap compared to UK schools, but when I actually total everything up (living costs, visa, flights, hidden school extras etc.) it probably worked out only hundreds of pounds cheaper to do it in the US.
Having said that the only reason I trained there was to get the PPL done in 4 weeks. UK weather isnt so reliable and it'd probably take you more like 5 months.
Personally I want to complete the rest of my training in the UK. It is more expensive but I dont think completing all of your training in the US then deciding to look for a job in Europe with no experience in European airspace is a particularly good idea... just a thought, I may be wrong...