Kicking myself as Last month I nearly booked UC return flights for this August for LHR to LAX. Went back on line on virgin website today and they have gone up by about £1000 a ticket!! Advice please... Are they likely to keep going up, or could they come back down again?!

The UC sale was on and that has now ended.
This won't help you now, but advice on these boards is to grab a price when you see it.