I use a search engine that posts UK dealer's products. It is obviously not fully comprehensive but it gives some indication.
There are 162 for sale at present with prices ranging from £3,950 down to £275.
Brigg of London appears to be the top maker. Here's the expensive one:
Mahdi of Khartoum walking stick sword stick.
On the silver collar is having the illustrious name Brigg of London. Hallmarked for 1902 made from Ebony Malachite silver horn and bone with a fine steel blade, overall condition is superb with no damage whatsoever a truly finely made of exceptional quality walking aid. Above the Briggs silver collar is a smaller one with what looks like Arabic symbols. This is the Flagship for anyone's collection. Total length of 94 cm diameter of handle is 5 cm the ebony sticks diameter from handle being 18 mm tapering down to the bottom 12 mm, from steel tip to the top of the handle is 85 cm.
£1,500 will get you one with a silver mustache comb and mirror secreted in the vulcanite handle. Obligatory in 1888 Birmingham!