Very rarely if ever would I be okay with paying double for a card based on what I valued it at. This is especially true if the card really doesn't fit a primary collecting need/want. However I made the decision to do just that at a card show back in February. I really wanted to buy something and for $10 I picked up a card worth $5 tops despite it being really cool and really old. Here's my newest boxing addition:
This beautiful 1938 Churchman's Cigarettes Boxing Personalities card of Henry Armstrong is slabbed an SGC 55 and was one of the oldest cards at the show that day.