Expensive setting and stone. For 1 carat, you should be able to get into the $6K range or so. My 1.01 was $4900, G color, VS1, round about 3 years ago.
Beautiful setting, but I'd highly suggest a 4 pronger, as the 6 tends to block a lot more light. The fire is generated by light entering through the bottom and sides, and refracting out the top, so you'll get more "bang for your buck" in the way of sparkle if you go 4. They should be able to modify the setting (and not charge you) so you can still have the very nice design you've shown.
One final note, even a VS1 stone could have a pretty unfavorable blemish, based on it's location alone. Even a small feather or inclusion, barely visible to the naked eye, could be located in a very unfavorable spot where it impacts more light than a stone with even more inclusion. spend lots of time looking through a selection of similarly priced stones, and try to get one with the blemish, however minute, closest to the edge and away from the center.
Overall, looks like you've got a very lucky lady.
