Here's another option for you that might save time and money since, based on your calculations, it appears you were planning on running your own oak logs to the sawmill. Take cash, saw and hammer in inventory and wield an axe, go to your house in Remmington. Exit portal and cut an inventory of oak logs. Go back into house in building mode, go to dining room, ring bell for butler, use logs on him and send him to the sawmill for 24 planks - less if it's not demon butler. Remove dining table, butler returns with planks, build and remove 4 carved oak tables. Repeat. I think the butler will ask for wages about every 10 trips or so. It is worth it to move your dining room to be adjacent to your portal while you train in this fashion. I used many methods and found this one to be the best for me :D