It always depends on a case by case basis such as card rarity, demand of the card, condition, etc. If you go in, they will be more than happy to talk to you about it and give you a better quote.
When selling cards to anyplace you will not get much more than 50% of value, if that, of the card due to them needing to resell and the time it may take to resell the card. Your best bet to find the cards value is to look on eBay for the card you want to sell and look through the completed sold auctions of the same card, sorted by the most recent, to determine the value someone is willing to pay for the card and sell it yourself.
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