Grading Coins With "Problems"

There are several theories on this.

"Net grading" is one option. You can lower the grade, based on how bad the problem is (maybe down to VF-20 for a very minor issue; one or even two whole grades for a more serious problem). I don't like this method, since some coins are only worth 10% less in the next lower grade, and others are worth 60% less.

When I record the values of the coins in my collection that have problems, I start with the full value for the grade, then deduct a certain percentage. I've chosen 10%, 25%, 50%, and 75% as the possible deductions and choose the appropriate one based on the severity of the issue.

I would grade it as "vf30 with problems". I don't try to assign a value, as the rarity and demand for the coin will determine whether the problem is an issue or not. If it is a difficult coin to find, then the problem, unless it is a major problem, probably wont affect value too much. Of course, this will only be an issue if you are selling it.