wow $3K?, Ive had 3 of the jumping cards with 2 in the EX range and could never get more than $300 for any of them.... It is far scarcer than the dugout card, but not worth 10X more.
Its really worth what you just paid for it.
PS they are really from 1947 not 1948, if you read the back of the dugout card it says "Born in George 28 years ago" so calling it a rookie is all good
good luck