The IRI is only 5 hours of flight training if adding privilieges to an existing FI(A) rating. So it is a relatively inexpensive add on.
The issue as you say is the cost of 30 hours p1 MEP, I was in a similar situation heavy TP time gave me the IF time to be an IRI but not the MEP time to be a MEI.
What is your situation, are you still flying in an airline, or are you now returning to FI work as a full time option?
At least in the UK the IRI gives the option of teaching the SEP IRR, and there isn't much demand for full SE IR or SE CB IR, as your location is Norway that is not relevant.
But for the integrated courses the SPIC and SE IF sections and even parts of MPL core phase (probably not that relevant given that most of the MPL courses have stopped) that are conducted in the SEP require an IRI. So yes for getting a job at the schools conducting integrated training the IRI even if SEP only is required.
The middle eastern schools have all advertised in recent months.