I'm not an expert on group buys, I've only been involved as a buyer in two or three and I've never honchoed or designed for one.
If I'm not mistaken the two main suppliers for group buys on Castboolits are NOE (Night Owl Express) in the US and MiHec in Slovenia (Europe).
In a couple of threads I've read that current production times are well over a year. One particular group buy was listed as production in December 2013!
The demand for semi-custom moulds of high quality is obiously great. So great that Miha Previc (spelling?) on MiHec moulds actually quit his daytime job and is now a mould maker for a living. This is admirable and I believe it to be a great sunshine story in which Castboolits has played a part!
However, I myself find myself not signing up on several interesting buys because of the long waiting times on both NOE and MiHec moulds. I have seen a lot of people even removing their names from the lists they signed up on when they realize the delivery dates. In the same time the mould makers usually do a couple of extra moulds in each buy, because they now someone will find the Closed Buys and will want to get in afterwards. Some members even do this systematically, looking in the Closed Buys section and write when they see something interesting. I have to admit that was how I myself got into group buys, I found a mould for a boolit I liked in a Closed Buy and asked if there were any spares. After that I have signed up in some lists and gotten the product.
Personally it would take a lot to buy anything else than MiHec, there is a huge cost difference as any US made mould will have a 25% tax fee added (calculated on shipping costs as well). This makes a NOE mould almost twice the price of a MiHec mould for me, and I know a lot of other Europeans think the same. This also goes for Lee, Mountain Moulds, Accurate Moulds, NEI etc. I would happily spend $100-200 a month on group buys if the delivery times were 4-6 weeks. As it is I'm happy if I get in on one or two buys a year.
So what can we as a community forum do to help reduce waiting times? Spread the buys among other manufacturers? High demand is of course desirable for any manufacturer, but as written above there is also an unknown amount of potential customers lost because of the waiting times.
I am not complaining, merely trying to improve for all our benefits, both the mould makers and us buyers.