Yeah ... learned that awhile ago. When I was buying cards regularly and trying to get 4x the whole set, I'd crack 2 boxes then buy the rest of the rares I didn't get off ebay. Worked out well. Ended up cheaper than buying a full case. Depends on the set's mytic prices and you luck in pulling the good ones! Only problem with buying 4x rares off Ebay is there's no chance at foils unless you pay the premium.

The problem I had with buying random packs is that even if you do hit the mythic jackpot ... you'll still probably end up with a card like "Cast Through Time".