Gore Tex,
There is a one off admin charge of converting your UK EASA licence to an IAA EASA licence which, from memory, is less than 300€. The UK CAA will also charge an admin fee for releasing your medical records to Ireland - about £50 I think but variable depending on how thick your medical file is. It can all be done via email and/or over the phone. The entire process does take several months.
Thereafter the IAA renewal service is free. The only ongoing charge is that every couple or three years you need to renew your EASA medical. This can be done in DXB and is about AED 1k.
Each year just print and email your OPC PPC paperwork (all 7 pages) to Dublin and include your medical renewal every 2-3 years and IAA will post your renewed licence paperwork to you in DXB foc.
Simple.