What Rob said - he beat me to it.
It seems the risk of being hit by customs is lower in France than in the UK : I've been ordering from BG on a regular basis for about five or six years now and have never paid duties once - and we're talking about twenty-five to thirty orders since around 2010 here.
Paul, here is my simple recommendation for what it's worth : keep your orders small and never buy more than $110/120 worth of goods at once, as that should allow you to slip under the radar. It's always best to split a large order into several smaller ones even if this method is more expensive postage-wise, and Lon Weiss is absolutely okay with that despite the extra work it entails for him.
Also, always use USPS (Lon only ships through them anyway) and never a private courier service such as UPS or FedEx, who will not only force customs duties on you but hit you with an additional 'handling fee' as well.
So far, this has worked for me just fine : so if it worked for Ile-de France, it should work for Auvergne too