Pine Tree Block

One of these on its own reads as a sapling. Keep feeding the same spot and the shape grows, and anything sitting directly above another block of it turns into trunk. That makes this the only tree in the game whose height and spread you choose, which is why it works indoors where a real sapling never would.

They come out of presents, and presents only drop in the back half of December, so your supply is capped by how much of that window you spend farming. Bring home far more than the build seems to need. They feed a whole furniture line and an alternate Pine Wood now, and going back for more means waiting a real year or lying to your system clock.

Raw blocks are worth almost nothing. Run them through the workbench into chairs and tables first and the same pile turns into real coin, which is a reasonable use for whatever is left when the decorating is done.