I have received vaccines in the DR, free and only with my cedula, before I was a citizen. I have seen nowhere any indication that medically expats are treated any different than Dominicans.
This vaccine is not like the cheap stuff that has been around in good supply for years.
For these "old" vaccines the producing companies have long ago recovered their development costs.
The CV19 vaccine have been rushed through in about 8 months with little regard to the development costs which in all likelihood are enormous.
Usual time for vaccine development is 8 to 10 years in normal times.
Take a look at the stock prices for Pfizer and Moderna.
The US government has Operation Warp Speed that includes some of the producer but not Pfizer.
For the US population the government wants as many people as possible to get the vaccine and will want it cheap or free with the government picking up the bill for Americans.
I think it is likely the vaccine producers will want to profit as much as possible on out of country sales.
The US government will likely not put any limits on out of country sales prices.
Buckle up for the prices.
You may want to take a short vacation back to Canada that will be free compared to this vaccine price in the DR.
Some vaccines are already pretty expensive in the US.
Shingrex which immunizes against Shingles is $175 to $200 per shot and you need two.
If the costs are sky high your health insurance will have to decide on how to offer this vaccine.
Maybe look to China or Russia for their vaccine which is already in use.
Hey, you put Chines tires on your car, why not a Chinese vaccine, eh
Just my view point. You have yours and we shall see. Hope it works out and we all get a vaccine of some sort.