I answered the way I did because, IMO, that is the way to go. Easily get 14kg (30lbs) in a bucket; batches can be kept separate if required; you WILL know how many jars you are likely to require; any honey which may be 'suspect', for any reason, can be kept separate and/or fed back to the bees if necessary; one always needs a buffer if supplying a demand on a regular basis and by 'the bucket' is a good way; warming a bucket of honey is easy if/when it crystallises; winter has to be negotiated, colonies may be lost, next season may be less good than this, even to the point of little or no crop.
Just a few reasons why I store my honey in buckets, before bottling. The primary reason is, therefore, I do not need to know how many jars - until all the chickens are hatched and counted, so as to speak. We have to remember that beekeeping is a practical hobby (or sometimes livelihood) and the theory certainly doesn't always match exactly.
If, as Admin says, bottles are sold by the gross, you will need to buy 2 gross; otherwise you may be 2 jars short! I think that adequately demonstrates the futility of trying to predict with any accuracy, the outcome - some months ahead of the result.
Regards, RAB