final questions before grading.

That depends entirely on the coins and how they grade. But, most coins from these sets will grade between PF64 and PF66. That means they will sell for from $10 - $25 each - roughly.

Now say the set cost you $30. Then it cost you $25 each to have the coins graded. That's $31 per coin.

So the question is, is it worth it to even have them graded ?

I'd have to say no. It doesn't make much sense to pay $31 for a coin when you can only sell it for $15.