I know it is random...though I wonder when on two accounts the "sorry" message seems to be the February flavor of the month! Some of the items take a bit of doing to get and to get them and proudly go to the mage and have him snub his nose at you...well it is downright grumpy and mean!
Would it be possible to adjust the mages demeanor every other day? In other words a counter if you get the sorry response one day you cannot get it the next day? That's a good compromise I think he can be grumpy half the time which I think he enjoys and the other half the hard working player gets a reward for his labor. Just an idea as I contemplate whether I want to continue suffering the indignity or sell off my items for some other more patient individual to await the grump!

With at least a single level response always available every day from the quartermaster daily quests it would make sense to make the daily mage quest more responsive especially since the items traded for that one level are far more labor intensive than what the QM asks for.