Just never pay anything upfront. I know quite a lot of people, who went to JAA schools in florida, where they paid upfront large amounts of money and have been really ripped off!! Once they had paid, the school didn't seem to care about them anymore: they had to wait for ages to get flights scheduled, then there were huge hidden costs like fuel surcharge, insurance.... It seemed that other guys who didn't pay upfront had priority for plane rentals.....Plus the instructors were unexperienced FAA pilots. I met someone who actually almost got killed by his instructor while doing his PPL..... I don't want to mention the schools names because some of them are paying pprune for advertising......
So be extra careful if u want to do "JAA" training in the US: Have a look at the school first, talk to students, ask them about all extra costs, fuel surcharge, insurance, price changes. And very important ask about refunds if u quit training with them for whatever reason. And get something written, that states that your money will be refunded if u quit!!!! Some schools won't even give u back what's left of your payment.....! And never ever pay more than 5k upfront!