Beacagusmeal, you spot that people are rightly cautious about guessing yield per hive, per year because there are so many factors to consider. But here goes ....
Say you have a good spring build up, you've got some nice willow, crocus and snow drops, a few blue bells and some rape near by. You could well get a super out of that. You harvest mid-late May.
Forage and nectar flow remains good through the early /mid summer, you harvest again mid august, you get a couple of supers this time. If you are lucky you might even get a fourth by september (or you have gone to the heather deliberately) if things are really going well, or if you didn't harvest then they may have used it because of poor forage (if you took it you are now feeding)
A well drawn super on 9 frames with deep comb can easily give 35lbs honey and newly drawn on 11 frames and shallow drawn perhaps 25 Lb. Your typical hive is then giving you anywhere between 50lbs in a duff but 'stable' year and 140+lbs in a good year. In a bad year (and we haven't included the possibility of swarming / forced splitting = worse), you've got next to nothing. If you are keeping to make money from honey with a couple of hives then it's unlikely given your costs and time.