It's about £2,500 ($3,100) per year in the UK if you just buy it online, not subsidised. I don't know how the US massive price hike is justified when the whole western world is buying it from the same supplier (Novo Nordisk in Denmark).
One counterpoint is that in my country we’ve successfully reduced prices for medicines a lot by strong negotiations in the last decade. We are last in line among western nations for medicines now. Shortages all around.
And the US isn't paying for the R&D (that sounds like a regurgitated line from somewhere?) so much as paying for the pharma company's profits, due to the US's totally screwed-up healthcare system and situation.