I am doing my IR first at the moment...
I would say it depends of your skills, that's simple.
If you have got a good PPL, go for IR. If your PPL is too light, go for CPL.
In my opinion CPL and IR are very different.
I had a good PPL because my instructor (who was an airline pilot) knew that I wanted to become a professionnal, so he taught me like a professionnal attitude no just a private.
So I don't have any problems for my IR now. And plus, others students with CPL find the IR difficult and have a little bit problems with Locator etc.
Each students learn on their pace. I really prefer IR, it is more interesting, you can fly through clouds and on the top, it is beautiful. Welcome IFR world!
Really, after my IFR I have to learn CPL, and I don't want... LOL I don't like VFR rules....
and I would say, IFR before you avoid 30 hours building... to pay...
The goal is to be paid for flying not to pay.