I'm conflicted. I have several series I've been working on for a decade (or two???) now because 1) I don't get to go to shops or shows more than once a year and 2) I like the hunt. I know I could find all of the coins I want online, but I like searching the tables and the shops for that perfect one. Not "perfect" as in MS-70, but... "the one".
Anywho, it's frustrating at times because I won't make any progress towards completing them. But I don't want to buy overpriced slabs from Heritage.