Check more than one store if you can
Or do what an increasing number of people do, and build an MTG Commander deck - it's a lot less painful to buy that mythic rare when you only need one copy.
We dont know how many are resubmissions, but it should give you a reasonable suspicion that between 10-25 copies from the pop of each card may be from employees and were not officially awarded to the winners
While it might happen for some unpopular Secret Lair drops (the foil basic lands were considered to be one of the worst of the original drops, which might help explain why it is the most valuable todayfewer copies of the foil snow-covered basics are on the market), in general, I'd expect most Secret Lair cards to mirror their original non-foil printing in terms of price
Had we instead increased the number of Japanese cards, the actual cost per card metric would have failed to account for duplicates
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