popps, they're really not all that rare, the majority of the population did the event.
Well, I looked around and Atlantic, for example, sells at 10 millions gold.
Less populated shards may have lower prices.
For Catskills I could not find any on vendors so am not sure in respect to Atlantic where would pricing be.
Though, considering that a shard I imagine similar to Catskills as far as population, like Lake Austin has one at 8 millions gold price tag, I would imagine that for Catskills a reasonable price could be around that (8 millions gold, that is...).
Truth is, that now that the Event is over these items are real rares as they cannot be obtained any longer.
As time goes by they will increase in their value since less and less will be available, increasingly.
This is even more valid for the Plucked Turkeys since many will disappear being traded at Butchers' for the Harvester's Blade (a cool item which increases by 10% resources harvested and puts them in backpack, automatically) thus reducing significantly the number of Plucked Turkeys around.
For the Harrow, which had a VERY low drop chance, I heard reports of a 50 millions gold value. Ain't that the worth of a rare ?