You may need to consider the restrictions that I would imagine are in place for official Gaeltacht (Irish speaking ) areas. Purchasers in these areas are , as far as I know required to be fluent speakers so that they do not effect the survival of the language as a live , spoken one in everyday usuage. Based on this assumption I would also imagine that 'investors' in this area would be closely scrutinized, being fairly contra to the policy re: fluency.
You may need to contact the local authority in the area to confirm what restrictions are in place. I would not rely on an Auctioneers advice.
I have to say that I do agree with the above policy,as these areas have been hard fought to retain and could easily be jeopardised by a few investors. I think there are a number of other investment options for your budget which probably would leave you with better returns togther with good conscience in protecting our national heritage.
If the law & planning does not protect or restrict these areas, then the decision is , ultimately, yours.