To answer your question directly, yes. You can scan them all at once and then crop out the card you need when loading them in the database. Time consuming but works. In ref to gb24's reply; you'll have to play around with your scanner to find out how and when it will separate each card on the scan bed. I've noticed with my Canon it depends on the gap/space I leave between each card. Too close together and it reads them as one object. I arrange mine pushed up against two edges on the scanner bed to keep them straight. I can typically do 5 cards at once and the scanner separates them out into individual images/objects.
Someday my cards may double in value and then be worth half of what I paid for them.