It seems to me their main international business is very word-of-mouth, relying on organic marketing like this thread. They could do better at that (and I do some work in that area; I'd be happy to work something out with them - maybe they could pay me in shoes although I'm not sure what my partners would say!)
But the problem is, there are a lot of makers in this situation. Meermin and Carmina we know about, new kids on the block like Ed et Al, and who knows what's next? Sure, Vass's prices are very competitive - especially if you're outside the EU - and what you get for your money is impressive, with every pair effectively a no-extra-charge MTO. The thing is, it makes the process of buying their shoes very human, a little time consuming, and the antithesis of the easy online experience most international buyers now use. That in turn denies them the opportunity of maximising their margins and growing.
As a shoe customer, maybe I shouldn't be saying they could make more money out of me with little or no pain at all. But they could. The most obvious way would be to do the simple things that their competitors do: make a standard selection, have a website where you can buy online with a credit card, from whatever is in stock, with shipping and VAT/no VAT made clear, and you just open up a whole new world. The bonus beyond that (for them) is then adding a standard MTO charge, and even MTO options with pictures on the site (like Bespoke England do for G&G, for example).
There are three ways great independent makers are messing up business-wise, from George Cleverley to Meermin: not being able to complete a transaction online. Not being able to make a detailed selection online. And not having in stock what is being sold online (G&G, Meermin). All of these things make the international (especially American) customer more likely to move on to another option. Vass should not underestimate how much people like to just buy something they've only seen online, pay with a card they trust, and receive an item from stock by DHL in three days.
It seems counter-intuitive to a maker of fine shoes, but in this "igent" generation, people really do just like to order what they want off the internet, not deal with any human beings at all, and get exactly what they ordered in the post. And we also are happy to pay to have our own order made up. Anything less than 30% for a MTO charge looks like bargain compared to others. No charge at all looks like suckers.
Put it this way: why the hell would people pay up to double for a pair of Vass shoes from a certain re-seller on eBay? Sure, perhaps not many people on this thread do, but someone's buying them or he wouldn't still sell that way. (Tombrone, your margins seem eminently reasonable, btw - I mean the other guy!). The reason people pay the price is because it's easy. There's a pair of shoes, in a certain make-up, in your size, at a price, and you can pay with PayPal and get them in a couple of days. That is just too appealing to a non shoe-nerd customer, when he's told the alternative is "email this guy called Rezslo to talk about what you want".
There's a lesson in there somewhere. Oh, and one more thing: get your generic domain back, Vass! Emailing a non-existent or non-responsive distributor who has your ".com" almost put me off trying to get Vass shoes at all.