This may be obvious but you can get a rough idea for how the fares are moving around by using the flexible fare option and look at each month between now and when you want to travel. We just booked EWR to SXM for 2 weeks, Wed 1/22 to Wed 2/5/2020. on United. $371 RT Basic Economy. We have the Mileage Plus Explorer Cards so we each get one bag checked free. We also paid an additional $70 to reserve all seats and $58 for travel insurance through United (AIG). It's a lot less expensive if you can travel mid week.