I've never purchased a high-end box because the risk/reward is so high that it doesn't justify the cost and I'm not banking on pulling such an extraordinary card that it would pay for the box and more. However, my collection does feature many high-end cards I managed to score for great prices from eBay. My latest is one of my collection's greatest and one of my all-time best steals.
I managed to score a redemption for a Ryan Getzlaf '11-'12 UD The Cup Limited Logos Auto/Patch /50 some time ago. They had routinely been going for near fifty clams when I landed mine for ~$23. I quickly redeemed it and soon thereafter the above beaut arrived in my mailbox. Numbered 16/50 - oh, so damn close - it features an INCREDIBLY AMAZING logo patch from the front of a Ducks' sweater. The inside of the big "D" includes a webbed duck foot, and my patch is that in its entirety, though part of it is hidden by the card. The auto is big and on-card which shouldn't be forgotten simply because the patch is patchtastic. This bad boy instantly becomes one of my favorite cards period and is certainly one of my most, if not my most, attractive Captain Getz.