Hi Spitfire
I think the CAA guy gave you some good advice.
after your exams and CPL your money is best spent on an instructors rating. Its better to remain instructing (only if you enjoy it and your students get value from you ! )until you have 500-600 hours TT. As this point you will ensure you get through the IR in the minimum approved course hours and your CV will look better than guys who are not in current flying practice and have very low P1 hours.
As an IRE I conduct about 70 renewals a year half of which are for guys who have not flown a twin since their last renewal or initial test but feel they must maintain the IR for the CV.
It is usual for them to require a sim trip followed by a dual flight with an insructor
before they feel comfortable at attemting the renewal (revalidation). The pass rate is very good because I do not fly the test unless the instructor conducting the dual flight is happy the guy will pass, I quess the typical cost is around £800 - £900.
Hope this helps Good Luck!