Saying a year 1 FO will gross around 85k is imo misleading. Yes by the time you add pension contributions & downroute subsistence allowances it will get to that amount but you won't see the pension money until you retire! Incidentally if you're on about a total package yr1 must be approaching a six figure sum by the time loss of licence, private medical cover(for the family), car parking, uniform, yearly class 1 medical etc etc is taken into the mix.
Year 1 gross pay is currently a shade over 69k rising yearly in line with the salary scales. Which from what I remember was about 36/3700 net monthly. Do not count on the allowances as income. They vary each month depending on your flights & by their very description are not meant to be thought of as income but subsistence money!
Virgin is a great place to work, I for one am very happy. If you're looking to get rich flying though I'd suggest you look elsewhere like the sandpit or Far East. If however you're looking for a decent UK based lifestyle, good luck with your application!