Many dates of Hong Kong subsidiary silver coinage ~ five-, ten- & twenty-cent pieces ~ are perhaps more difficult to locate than even the more aggressively-collected half- and one-dollar coins of 1866-68. Key dates in the ten-cent series are 1864 and 1905 and some semi-keys would be 1865, 1872-H, 1873, 1873-H, 1874-H, 1875-H and perhaps 1883-H and 1890. All are scarce in almost any condition; even so, IMO they are a much greater bargain if "raw" and UNGRADED. Graded coins seem to be aggressively bid up to ridiculous levels by collectors from China proper: instead, avoid them and try for genuine examples of truly scarce dates in lower grades. You may not even have much bidding competition!
This 1864 cost @US$300; the 1872-H about US$250...
