For the past year I have been obsessed with coin collecting and devouring any piece of information I can get my hands on. My grandfather left me a set of circulated walking liberties and I have been hooked ever since. I've realized for a while that my heart is set on deep cameo proofs and I have decided that I want to start a set. Now I do plan on the '36-'42 sets as well even though only a few cameo coins are known. I also understand the from '50-54', dcam is quite the expenditure. However,I plan to focus on 55'-present in deep cameo. I'd like to buy sets in the original holders from '78-present because after a read of a guide book of modern United States proof sets, I've learned that coins from '77 and before aren't a guarantee to be dcam. So, for the coins that I buy certified, what is a great grade to go? I've been thinking of pf-67 but I just want a few opinions. Thanks!