We were a bit put off by the SVG Air cost back in 2010 when we chartered with Barefoot out of St. Vincent. The differential you quote does not see bad, however.

Sooooooo, if you've got the clams I'd think it's the way to go.

I'm not a big fan of LIAT. We booked two extra days into our trip to accommodate for expected problems with LIAT. It turned out that they lost one bag on the way down, and we got it 24-hours later, so that extra day was fortuitous. They also lost a bag of our crew who flew in a day later, but thankfully the bag showed up at 10pm that night. Kaishawn (Barefoot's Taxi driver) saved the day by fetching it for us from the airport late at night! It had all of Lisa's clothes, so she was sweating it big-time! Kaishawn is a great guy. Also, it turns out that we enjoyed our extra two days and the more relaxing pace for travel that it afforded. However, all-in-all, booking two extra days for the trip including hotels is probably more expensive than the additional cost of the SVG Air charter flight.