Also, as I just discovered, a $20 gift card does not cost the giver the same as a $20 bill. When the card goes unredeemed, or the store files for bankruptcy or closes, the giver threw away $20. When the giver sends a $20 bill, that bill is then exchanged for goods or services of equal value.

You are risking spending more for the card than the cash, and in this economy, the risk is higher than normal.