Ok,
You don't need to do a full Initial IR any more. Details are on the CAA's website. You can do a minimum of 15 hours to convert your IR.
That however, will give you a JAR CPL with ATPL credits.
If you do a type rating, you will get a JAR ATPL with a multi pilot IR only.
Is the Shed cheaper than the abridged IR?
No.
The CAA made me do lim panel, stalls, steep turns as well as a couple of ILS's and an NDB. (plus holds, plus various other bits and pieces). This increased the cost of the Shed rating considerably.
The CAA seem to put emphasis on different areas (compared to CASA). You may not have busted any minima's or tracking tolerances but you may still get fail items on an IR because you didn't maintain your nominated speeds, fail to do the checklist when they think you should have. Get very good advice and preparation for that check.