4.6sara
The EAS system on the P38 does suffer from more than its fair share of problems, especially on vehicles near 15 years old, and since EAS is not fitted to many other vehicles, your average general multi model Garage typically runs a mile or wants a fortune to get involved as you seem to have discovered.
You could find a good specialist indie, and there are plenty, but again that won't be that cheap and may well not be a one time visit during the time you own the vehicle. Alternatively you could bite the bullet and sus the problem out yourself, and at the same time pre arm yourself with knowledge that will always stand you in good stead for whatever the future might throw at you.
The EAS was after all, not designed by some super intelligent alien race, In fact many might agree that "Morons from outer space" would be more apt. it's elements are quite within the grasp of even the most blonde essex girl. There is an absolute ton of information and reference material on the web from plain folk who have managed perfectly well and already this thread is brimming with very sound support and advice. So whatever you do, please do not feel alone or un supported.
Not mentioned thus far is getting some equipment to access the EAS's built in self diagnostic capability. I am not specifically advocating our own here, as there is quite capable free software availiable that requires a very minimal cost interface that will allow you to read and reset any fault codes from the P38's EAS system for not a lot of outlay.
Best of luck