The UK CAA now accepts other JAA medicals from other countries with a validation letter. The IAA accepts UK CAA medicals.
Generally speaking, flying training isn´t cheap, and if you shop around, you might find it more affordable in other places, but you also get what you pay for. I got burned once trying to save a little bit of money doing flight training.
If you start looking around on this forum, you will see reviews of many different flight schools, things ranging from ¨this place is awesome¨ to ¨I would rather my sister date Joran Vandersloot than send her to this place.¨
Goodluck