The Skybound USB adaptor including software is $149. NavData is around
$360 for 13 28-day updates.

Be aware that the new WAAS upgrade has an 8mb card instead of the 4mb
card used in the 430. I called Jepp and they don't seem clear whether
the existing USB adaptor will function with the new card.

A related question on WAAS is how one would update the terrain card.
Terrain data comes from Garmin so might require a separate adaptor.