Splitting time between the DR and somewhere in Europe is expensive. Especially if you don't live close to a main European hub.
Since Covid I have been paying 1000€ GVA-MAD-SDQ with Iberia.
That's base fare, I usually end up paying 1300€ --- I think---- for premiumsomethingorother economy.
It also allows me to change the return dates twice w/o fee.
Then I pay 300 or 400 pesos, depending whether I can be bothered haggling, for a taxi to take me to the CaribeTour station.
And 600 pesos bus ticket that gets me up north.
It makes it a long day, I leave my house in Europe around 05.00 and arrive in my house in the DR around 20.00, the same day.