What kind of wood are you looking at for $400 / board-foot? Is this for a pre-edged, pre-finished baseplate kit with gold stanchions?
If you're looking for a small piece of lumber, our shop probably puts enough walnut/cherry/maple/poplar into the scrap bin to build 100 model ships per day. Employees then take this home and burn it for firewood. I can't get into the business of providing wood to all the members here, but if you just need a piece of nice wood of the above mentioned species that is large enough for a base, I could probably pull one out of the scrap bin and get it to you for just postage costs.
Also, if you plan on covering it with a mirror, it doesn't even have to be that nice. The tricky part will be drilling holes in the glass for the stanchions.