If you go with an estate agent (and I can't see how you can avoid it if you are overseas) you will be charged a marketing fee on top of the commission that they get from the sale. This marketing fee covers a professional photographer taking pix of the house, putting the listing up on daft.ie and myhome.ie, getting a sign put up, flyers printed etc etc. Estate agents normally require this marketing fee to be paid up front so that they are not out of pocket these expenses if you change your mind about selling the house later on.
You will also need to have a BER inspection done to rate the insulation in the house. The house can not be sold without a BER cert. When I sold my house last year, the up front marketing fee was 600 euros, and the BER inspection was 200 euros.
In these post Celtic Tiger days, 1% of the sale price seems to be the industry standard for estate agent commissions. If you are being charged 2%, they better be doing something over and above what other estate agents are doing for you.
When I sold my house, I can't think of anything that I was billed for that did not seem reasonable, or that I was not told about ahead of time. Get the estate agent to outline all fees and charges before you sign up with them. If you think that you are being hoodwinked, speak up and question it.