I've just looked on Addall, and there are numerous copies of this publication available, including a couple for 1933. The asking price is £30, but I suspect they are slow moving items, and will hang around for a long time looking for a buyer. I wouldn't let it go for less than £20, because, if there is someone out there who needs a copy, then they'll pay at least that for it, and a lower price won't attract more buyers.

Good luck!!!