In Australia it costs $38 (US $29) for a twin-pack of Epipens under our Pharmaceutical Benefits Scheme. We can also buy a single pen privately without prescription for $99 (US $75).
Epipens come in a grand total of 2 sizes to cover everyone from small children to very large adults, I feel like the precision of the dose isn't that important...
"Mylan's efforts to maintain its market dominance were aided when Sanofi's competing product was recalled in November 2015 and further when Teva's generic competitor was rejected by the FDA in March 2016.[76]"
Yes, you can load a precise dose into a device, but the device has to actually work, reliably and consistently. This is apparently a hard problem, for at least two Epipen competitors. Since Epipen has no serious competitors for a device like this, they get to charge as much as they dare.
I seriously doubt they would be handing out 1mg doses like candy if it was as dangerous as you suggest. China has actually been quite strong with controlling potentially fatal drug distribution in the last 15 years, tightening rules for many substances. The key reason is suicide prevention. Wikipedia says "Although it is commonly believed that administration of adrenaline may cause heart failure by constricting coronary arteries, this is not the case" https://en.wikipedia.org/wiki/Epinephrine#Adverse_effects
(Edit reply to a3n below: My point was that it's not as dangerous as you are making out, not emotional appeals and cultural norms for responsible parenting. Self-administration: good enough for 3 billion+ in China/India/other developing world locations, good enough for me. The whole idea of stabbing yourself with a fat dose of adrenaline is pretty hackish anyway and shows how undeveloped our medical knowledge still is.)
FWIW, LD50 dosage is low for intravenous injection, but very high (multiple orders of magnitude higher) for intramuscular injection. The risk is generally not getting enough of a dosage, not too little, unless you somehow manage to hit a vein.
The main problem is that, if you're carrying around EpiPens for allergic anaphylaxis, particularly for a child, dealing with syringes and bottles isn't really a practical solution for day-to-day living (and definitely not an option if you're carrying them around for yourself -- hard to carry out delicate medical procedures while being unable to breathe). There are probably a lot of people without access to autoinjectors who have had to suffer the consequences of anaphylactic shock.
If you're injecting with a traditional syringe, you can see how much you're drawing into the syringe, and presumably can create an accurate dose. Assuming you aren't untrained and panicking.
The idea behind the auto injectors is accuracy with relatively little training and skill; a parent can do it while they're watching their kid strangle. That's why you buy an auto injector instead of syringes.
Competing auto injectors have not been as accurate and simple to use, is what I've read.
I would not trust my kid's life to a hacker injector; these are medical devices that are required to go through trials. Even traditional syringes are regulated. Sure, maybe you can decide to use an unregulated injector; I wouldn't, not for my kid.
Except this isn't a purely hacker-built injector. They're using an off the shelf FDA approved injector sold as suitable for diabetics including use by children and the elderly.
The hack is putting in your own needle + medicine.
That means the epinephrine (adrenalin) itself is essentially free. What do they charge in the US/Europe/Australia?