Longer term? They are only available for a few weeks every year. The price will go back to normal around August time as people will have used the majority of them.
As for the collectables, like all the others in Torn they will either remain the same as Ched will add something different or they'll become another worthless, useless item.
No. Anything in christmas town now will go up over the next year. Its a good way to make tc play money long term. Hoover up the cheap christmas stuff now ANY of it. Look at the item graphs.
Turkey Baster for my display as it was the only one i didn't have from previous years (although they have all now become worthless as the previously limited items has suddenly become common - shame they didn't think to add a '17 on the end of the titles). The rest on booze. Nerve has far more value (to me) than happiness/candy