Thank you for your prompt response.
I have been researching in Ireland for over 30 years and have a database of over 30 000 names together with over 200 Hughes family pedigrees for County Louth where my clan came from.
I much prefer doing the hard digging myself as from experience a third party does not have the same eye for spotting things, nor do they have the same personal interest.
However, in the absence of knowledge of the system in Argentina, there is little else one can do but engage a research agent and cough up. Probably the best course is to pay by results and not pay a lump sum up front. That way you can pull the plug if you are not happy. Most researchers work this way in the UK and they will refer back to you to ask if you want a particular line pursued and you then pay a further fee.
Anyway, good luck with your research and if your researcher in Argentine comes up with the goods kindly let me know as I may engage her. At the moment I am pursuing a line of enquiry in London which might produce results.