So if I go into a store to buy a product with just enough crypto, but before buying the item, crypto prices drop. Will my card still have the same value as before the price drop?
You will be purchasing the item using a store gift card bought through the Zeex protocol with crypto. As soon as you buy your gift card, that card will have a fixed value in fiat so it will not fluctuate with the crypto market
This article explains more about the Zeex protocol:
https://medium.com/the-zeex-protocol/zeex-crypto-to-product-no-fiat-no-fees-872602f1faa3