So try and not let it get that far as it can become expensive.
Too right, the whole JAA type rating system is one big cash-cow. Why can't we have ONE type rating for single engine piston, and ONE for single-turbine etc. No school/private owner is going to let someone take a heli off on their own unless they had at least "differences training" anyway.
The fixed wing world has class ratings (eg Single Engine Land) - why can't we?
I can't beleive the CAA group the Hughes 500 and the B206 together for the purposes of renewing (the only connection is they share the same engine - very different handling characteristics etc) but they won't group together the R22 and R44.
Then again when has the CAA ever made sense on anything to do with helicopters? It seems like they treat the GA heli world as annoyance.