I have been waiting as well and knew full well that I would. As stated before, he has a smallish shop. When there is a group buy everyone and their brother run to the bank and get a loan. A smaller shop can not handle huge fluctuations in orders. They cannot staff for the peaks and have to try to find a point where they can keep all their staff busy, but not too busy or, worse yet, have to lay people off.
This is what happens in a free market economy when the economic picture improves. So, due to the enormous, for him, influx of orders, he is probably working some staff a limited amount overtime to fulfill our orders in which we got 10% off (he is losing 20% of his profit, just a guess). He can't stay in business paying a bunch of overtime so, to be able to offer the product at a reduced wait, we will have to wait. For my $s, it is worth it.
I do agree, for someone who may not have Luke's impeccable reputation, that a return call (or in this case, dozens of calls more than likely) it would be a concern. But as stated before, every 5 minute call probably costs him up to 10 minutes of lost work. It adds up quickly. So, I won't bug him or his staff. If he has questions for me, he will call me when he needs to.