Guys I've found this on LASORS in section E 1.2
SE IR(A) to ME IR(A)*
a. 5 hours instrument time under instruction in ME
aeroplanes, which may include (b);
b. 3 hours in FNPT II or Flight Simulator if approved by
CAA;
c. Pass a ME IR(A) Skill Test with a UK CAA Staff
Flight Examiner.
* The holder of a SE IR(A) wishing to upgrade to ME IR(A)
shall either hold a multi-engine type/class rating, or have
at least completed an approved course of training for the
ME class rating.
it's sounds cheaper

did they change the rule? or maybe I got the wrong section?
I'm very interested because I'm going to start the IR soon and I'd like to know if it's worth paying a little more for both the ratings:single and multi IR.
Thanks.