Would you consider an overnight stay in SJU? We can fly to SJU for really great prices. Its become our habit to do a stop over in SJU and then on to VG or STT (in our case) the next day. Breaks up the trip and we arrive refreshed.

We have chartered with Island Birds that past couple of trips and it can be cheaper or just slightly more than flying commercial all the way to EIS.

Often the first flight on the morning on Cape Air or Seaborne is really cheap.