Being a small company with a very focused mission, it is not like the larger manufacturers. For a 3rd Rail / GGD/ Sunset project the numbers of units manufactured normally falls in this range:
Brass Steam: 100 models typical, but will sometimes move forward with 75 orders.
Plastic Diesel: 750 units minimum with a minimum of 20 units for a paint scheme and road specific details. For example the E8/E9 currently in production has 30 paint schemes in one run.
Aluminum and Plastic Passenger Cars: Typically a 2000 car commitment so approximately 250 sets for an 8 car set.
Having said that, the Mollie does show up from time to time on that auction site.