I already own the agilebits store version and I am no longer comfortable with using Dropbox.
Sounds like you bought more than 30 days ago. In which case Agile will almost certainly not give you a refund. If purchase was 30 days or less ago, then they have a refund policy.
Just as a matter of interest, why are you no longer comfortable with Dropbox?
@campjh: danco is correct: if you've purchased 1Password within the past 30 days we can give you a full refund. Just contact us at support+licenses at agilebits dot com and we will take care of you!
But more importantly, your 1Password data is secure independent of the sync service you use, since it is encrypted before it even leaves your computer. This is by design, so that -- even if your Dropbox or iCloud account were to fall into the wrong hands -- an attacker would not be able to decrypt your 1Password data without your Master Password -- which neither AgileBits, nor Apple, nor Dropbox possesses.
I hope this helps. Please let us know if you have any questions!