Why would anybody want to buy Corned Beef for St. Patrick's Day. The Irish never ate the stuff. Beef was corned in and around the Cork region of Ireland from the late 1600s ( when the English took control) to the early 1800s but this was almost exclusively for export to England and Europe and was not commonly eaten by the natives. Most people in Ireland agree that corned beef first appeared in cans during the War and to my knowledge that is the only way it is still available there.
The true traditional meal would be bacon and cabbage.
Just so you won't forget, here is a little poem!
I just want to put something straight
About what should be on your plate,
If it's corned beef you're makin'
You're sadly mistaken,
That isn't what Irishmen ate.

If you ever go over the pond
You'll find it's of bacon they're fond,
All crispy and fried,
With some cabbage beside,
And a big scoop of praties beyond.

Your average Pat was a peasant
Who could not afford beef or pheasant.
On the end of his fork
Was a bit of salt pork,
As a change from potatoes 'twas pleasant.

This custom the Yanks have invented,
Is an error they've never repented,
But bacon's the stuff
That all Irishmen scoff,
With fried cabbage it is supplemented.

So please get it right this St. Paddy's.
Don't feed this old beef to your daddies.
It may be much flasher,
But a simple old rasher,
Is what you should eat with your tatties.