declared value question?

Sets

I know it's a stupid question, but, Do mid grade 4-5-6 Mickey Mantle cards from the 60's qualify for under the $100 declared value using the March $4.50 special? What happens if a higher grade card is submitted too, can it still get a high grade or is not graded, because it's in the wrong tier/price level etc. I never quite understood the declared value concept, I assume it's for insurance purposes. Any help appreciated.