Actually a hand-knit Aran sweater in the traditional Irish Fisherman style will take a knitter much longer than two days. Most knitters can work only a few hours each day due to stress on the hands and shoulders. This expert says ten days is the absolute minimum.
http://thewildgeese.irish/profiles/blogs/the-guardian-of-the-aran-knitting-tradition
Each sweater represents some 40-50 hours of work by a hand knitter ( I knit one years ago and I probably spent over 200 hours, but I am not an expert). Look again at the figures in the post above. Of that 300 euros, the shop gets half. That leaves €150 for the knitter, but she must buy the yarn out of that. So maybe €100 for all her work.
These days, the Aran sweaters sold in Ireland are of three types: hand-knit, hand-loomed, and machine knit. All three can say they were "made in Ireland" or "crafted in Ireland" if they truly were. The machine-made sweaters use merino wool (which may be imported) instead of the traditional Irish Donegal wool. They are lighter weight and more loosely knit, and come in an array of colors. The hand-knit sweaters should come with a label with the name of the knitter, and will be undyed local wool, mostly ivory but I have seen them in dark wool as well.
http://www.irishcultureandcustoms.com/AEmblem/Sweaters.html
The price difference is substantial. Looking online, I see "Aran" sweaters made in Ireland and sold by Irish companies for under $100. Of course these are machine made. There is nothing wrong with these; they are still pure wool (or should be), made in Ireland, and look nice. As they are not as heavy as a hand-knit sweater, they might be easier to wear. My own hand-knit Irish sweater was too warm for me to wear once I left Alaska.
So if you want a hand-knit sweater, you will have to pay the price. You will be buying not just a souvenir but an heirloom, as it will last forever (as long as you care for it and protest it from moths).
If you simply want a souvenir made in Ireland, with a choice of colors, and possibly a more wearable weight, go ahead and buy a machine-knit one, but get a guarantee that it was indeed knitted in Ireland. ( It is likely that the people running the knitting machines are not themselves Irish, but I do not know the story on that).