The Dominican Republic minted these nice coins to commemorate the visit of Pope John Paul II in 1979.
100 PESOS: 0.3472 troy ounces gold content
250 PESOS: 0.8999 ounces gold
Because these coins were minted for non-circulation, you can usually find them in brilliant uncirculated condition. Their value is equal to their gold content, plus a few dollars to account for collector demand.
For instance, if gold is trading at $1300 US dollars per troy ounce (see web sites such as kitco.com), multiply by either 0.3472 for 100 pesos or 0.8999 for 250 pesos to get the gold value: 0.3472 x 1300 = $450 US dollars gold value for 100 pesos, 0.8999 x 1300 = $1170 US dollars gold value for 250 pesos.
Once you have the gold value, add about $25 to account for collector demand. If the coin is damaged, say, with a fingerprint, do not add the collector premium.