Like many countries over the centuries, Costa Rick used counterstamps on other country's coinage to claim it as their own. There are several types of counterstamps, and several types of host coins. Requester Chilecollector has a Type IV counterstamp on a Spanish 1 real 'cob' host. These coins are valuable and avidly collected.
Our primary picture at the upper left is of a Type IV counterstamp on a 4 reales cob. This coin is in superb condition and is very rare. It was sold by Heritage Auctions for $8000 US dollars during a 2015 auction.
Most Type IV counterstamped reals are much less valuable than Heritage's 4 reales.
The picture to the left shows two 1 real cobs with the Type IV counterstamp. The (A) coin sold at auction for $300 and the (B) coin for $100.
The 3-to-1 difference could be due to normal fluctuations at coin auctions, or the (A) coin could have sold for more that the (B) coin because it is better centered.
Summarizing as best as possible:
1 REAL COUNTERSTAMPED COB:
crude: $100 US dollars approximate catalog value
4 REALES COUNTERSTAMPED COB:
crude: $1000 US dollars approximate catalog value