The PPL is a minimum of 45 hours of training.
The CPL is a minimum of 25 hours of training, but for a combined CPL / MEP it would be 17/18 hours training in a single and 7/8 hours training in a twin.
The combined CPL / twin test will save you an examiners fee, but if you fail or partial then retaking the test in a twin will soon start to mount up.
So the CPL is actually more expensive per flight hour, also factor in the cost of the hour building between the PPL and CPL.
Be very careful using JAA approved schools in America, not so much an issue with the training standard, it is just some of the characters involved in running flight schools in the US have had interesting pasts.
So make sure you research the schools history, it is hasn't been unknown for a school to go bankrupt with students money and then to find the same set of people running a new school a few months later.
Quite often these JAA schools do mark up the prices for the JAA approval, so if you are going to train state side it is better to do FAA ratings and the convert them back in Europe.
A single engine CPL without the MEP/ IR will allow you to do paid instructing, if you get the FI rating. In Europe single engine GA jobs which you could do in theory without the MEP/ IR are quite rare (aerial photography, banner towing, scenic flights, para dropping).