These are nice-looking coins from South Korea. The catalogs show that all but one particular date carry the following values:
worn: less than $1 US dollar approximate catalog value
average circulated: less than $1
well preserved: $2
fully uncirculated: $8
The one 'good date' is 1987. It can reach as high as $20 in fully uncirculated condition.
Please read our Important Terminology page to understand how catalog values work.