I haven't gone through having my cards evaluated by PSA for a few reasons. Mostly, because it's a long and fairly expensive process, that may not pay off. A card that looks "mint" to you and I might get evaluated as a 6 or a 7. That's still a perfectly good card, but in the minds of a lot of collectors it suggests the card isn't in great condition.
But, if you've got some potentially high value cards that look like they're in pristine shape, it may be worth it.