Interesting.
I tried to start up a business selling flats in the 1970's I think one of the first, my main outlet was the BMSS monthly shows where I had a table to display my wares, mainly Ochel, Hafer and I few odd figures purchased from E Bay., incidentally this is where I fist met Jim Woodley who at that time collected solid figures mainly German items.
The first problem was not the cost of the figures but opposition to the project from the BMSS committee who put many obstacles in the way as they did not want flat figures contaminating their shows. Later they did accept the flats had a place mainly due to the gift of trophies, by then I had stopped trying to sell flats.
The main problems with flats as withal all hobbies these days is that the demographics of society have changed with the introduction of electronic games and the changes in people themselves, collecting is mainly the prerogative of a dying breed and as this section gets smaller and smaller so will the demand for Model Soldiers, Railways and Aircraft until perhaps the collector will disappear completely.
The seller must always remember that without the Public buying their product they will have no business, and they must if they want to sell regardless of the cost price their end product irrespective of what that product is to sell. Too high no sales, to cheap no sales.
For many years I used to sell toys and models at the now defunct Toy Fairs and it is safe to say that when buying or supplying stock about 10 % would sell immediately, another 10% would sell over 3 months and so on, after about a year you would have 30/40% of the stock left, that stock was usually dumped at below cost to try and recover some cash.
Economics are a sad fact of any business but they always apply irrespective of what you sell and how you sell it.
BZ I imaging lose many possible sales as they are expensive but editors sell to them to finance other projects but eventually even BZ will go out of business, it may take years but in reality it will only need a small change in public opinion
Hope that I have not been too dismal but these factors effect business.
Kindest regards
Bob.