I would guess that a significant cost is the customer support.
You would have to assemble a team of folks and get them up to speed on the various Macs the cards run in. And you need to create the packaging and get retail channels set up.
No matter how large or red I make the notes on our website we still get at least 1 person a week who thinks they got a bad card because it won't boot up in 10.8.5 or 10.9. Someone has to answer that email and walk them through installing Nvidia Drivers. Also get at least 1 person a week who thinks the power plugs are optional.
Yes,we have FAQ and a Blog that clarify all of that but still people insist on getting these answers directly handed to them. So we answer the same questions over and over. Keep in mind that most recent Mac cards were from a specific "board partner". Sapphire, PNY, EVGA, etc. So those PC centric companies suddenly have to become Apple experts with a staff trained to know the machines, cards and drivers.
And I am convinced that Apple plays a larger role in those cards then we know.
The Mac 7950 was an enigma. It had an EBC rom that gave lovely boot screens on a 1,1. It seemed like the perfect upgrade for these older machines. It even shipped with a disk of 10.7.5 drivers, the last OS officially supported by 1,1. But somehow, the 32bit driver had a bug while the 64bit one was fine. I don't believe that was an accident. I think Apple insisted that there be no easy way to use those cards in a 1,1. Until Tiamo gave us the modded boot.efi there was no other option.
I remember it took WEEKS to mod the EFI to work on the Fermi GTX5xx cards. I finally finished first internally powered GTX580 and shipped it off, waiting for the glowing review. Instead I got a fleet of frantic phone calls and emails from a screeching customer. The card was glitchy and unstable and the computer kept turning off !!!! When he finally sent me a picture of the install I saw a single 6 pin cable split into 2. When i pointed this out he couldn't grasp that it meant there wasn't enough power for the card. He returned it, convinced the card was horribly faulty.
Which leads me to returns. People have gotten used to returning and returning things without ever considering that perhaps they should have researched their purchase in advance. We get 1 or 2 a week from people who think the card is faulty because it didn't speed up something that is 100% CPU. And of course they are angry and think card is faulty and I should refund them full shipping, etc.
And then there is fraud. We have had 3 cards shipped to an address in Portland that ended up being an overseas shipper. A few months later I got an email about fraudulent credit cards. I am just OUT $1,500. The cards are gone and so is the money.
And sometimes when you get the return it is obvious that someone got a little eager during the install and scrapped the edge of the slot against the back of the card, knocking off components. There is no way to get customer to pay, it is always the seller's problem. So the testing and repair takes a lot of time.
In short, it is a lot of work, and we do it on a small scale.
Did I mention that every month or so I have an e-waste guy come and haul away a tub of dead GPUs? Sometimes I get stuck with the hot potato and end up eating that expense as well.
It's harder then just slapping it in a PC and running a flash program.
