It's funny in an "I can imagine one of my players coming up with this" way. Quirky and original, too. Not entirely practical, but for a lighthearted campaign quite useful. Have a 4/5
On a side note, imagine super magical birds being the supreme rulers, and their envoys carrying their bird houses hence and forth. Perhaps the UberBird has its BirdPalace linked to a hundred portable StaffBirdHouses!
I think this is a brilliant item - a wonderful take on a portable extradimensional space.
An elaboration on the enchanted furniture would be a sentiant construct or more, that were responsible for maintaining order. These would be named and have real personalities, and get annoyed when the staff was signifcantly disrupted.
I would reduce the impact of using it as a walking stick as otherwise the constructs would go batty :)
Now, if the mage happend to take a tumble from a horse, or had to use it in combat, he would fret about having to deal with his annoyed servants.
Brilliant! I would love to see a quest where a party of newbies is convinced to become partners in this sort of "business venture." Their sponsor gives them a sample of the *very expensive* chalk, talks up the potential market value of the product, and strokes their egos a little. He then has them sign a contract as harvesters, and gives them vague directions to the nearest source. When they arrive, their contact in the area explains exactly what they are supposed to do. . . and reminds them of the severance agreement in the contract they signed if they refuse to go through with collecting these things.