Ouch! What Tesco did you see it in as a matter of interest?
I remember before, maybe 2-3 years ago, Tesco dropped the Carlow beers to 1.99, then put them up to 2.85, then dropped them to 2.79 and put up a "Massive Reductions" type sign. I'm surprised they've stayed at 1.99 this long.
Maybe they're about to jack up the price of the rest again, to match the IPA