Are VS missing an Upper Fare Sale?

On EVERY destination to the US I've plugged in today (while looking for one very specific trip), UA and BA have BOTH come in at less than half the VS price.
So, I'm looking for a very specific route. On that, UA come in at £1,588, BA at £1,598, VS at £3,919 [:0]
ALL airlines are showing 7's, so it's not an availability issue. I can't find anything promoting the other sales for UA/BA, but surely VS have missed something here? [y]
As it is, "welcome back" say the other two on my next trip - I can't justify 2.5x the price for the exact same flights! [V]
So, I'm looking for a very specific route. On that, UA come in at £1,588, BA at £1,598, VS at £3,919 [:0]
ALL airlines are showing 7's, so it's not an availability issue. I can't find anything promoting the other sales for UA/BA, but surely VS have missed something here? [y]
As it is, "welcome back" say the other two on my next trip - I can't justify 2.5x the price for the exact same flights! [V]