It is best to get a coin catalog to look up this coin. There are many variations. For example, the Standard Catalog of World Coins (1901-2000) lists 26 different patterns for the Hupeh 10 cash coin. Many of them have the legend TAI CHING TI KUO COPPER COIN. The one in our picture does not have this legend. Each of the 26 patterns carry approximately the same values, so the listings below give approximate catalog values, averaged over the many different patterns.
Chinese coins are hot. They are emerging into numismatics (coin collecting) in a big way. These values will probably go out-of-date fairly quickly, within a year or two.
worn: $5 US dollars approximate catalog value
average circulated: $15
well preserved: $30
worn: $2 US dollars approximate catalog value
average circulated: $8
well preserved: $15
worn: $150 US dollars approximate catalog value
average circulated: $450
well preserved: $1200
As you can see, the 20 cash is very rare; 10 cash are common.
Use the Important Terminology page (link at upper left) to convert catalog values to actual buy and sell values.