Question: Are there any rules of thumb for evaluating the value of holed coins versus unholed coins of the same condition?
Answer: Generally holed pieces are desirable only as fillers, unless they are of a particularly rare date. Over the years quite a few holed coins — such as 1796 quarters, 1794 silver dollars, and the like — have been expertly repaired and have found new markets, sometimes with the repairs mentioned and sometimes not.
However, there are some coins that are available only in holed form and are eminently desirable as such, as that is the way they were used — such as the 1820 North West Co. " beaver" token, certain political tokens, etc.