The best way to sell cards:
1) Common cards: Give 'em away or sell as a single lot. Those with large collections have no need of them and will be LESS likely to buy a mixed lot because they have to haul it home and then sort through it.
2) Uncommon / etc. Again, probably sell as one lot. If you have multiple "types" you may want to split them up (e.g. "Black", "Blue", "Red", etc.)
3) Rare: Here's where you make your money. You can package them in smaller lots (perhaps even singles). Make sure to detail exactly what cards are in the lot. Many people might be looking for a specific card and mentioning one may be the deal maker!
4) If you have complete sets (e.g. your binders?) then that is a good way to sell them too. If you're missing a few from the set, make sure to note that on the tag. Our auctioneers are brutal if you mis-represent an item!
We actually have some card experts on staff, so bring them in Wednesday before the con and they can help
L5R is usually pretty popular, but I don't know much about those cards.