I am going to make some interior door frames. The walls in the house are plaster and because of this, prehung doors are too narrow. The doors will be relatively light (hollow core). I was wondering what would you guys recommend as a good but not too expensive material to use. Is there anything cheaper than poplar that anyone would recommend. Or is poplar about the best that I can go with? I have used poplar before (most of the time), but it is not cheap. Thanks