What is a pacasso printed in 1968 worth?

It would depend on if it's an original or a reproduction among many other factors. In the late sixties he did a lot of copperplate etchings. So it's possible you might have one.

Etchings can be printed again long after someone dies. People also get confused because to an untrained eye it could look original. Etchings are notorious for being forged as coming from an original series. So without seeing some pictures it's next to impossible to tell what you have. Post some maybe?