Do those kind of prices come back or once they’re gone they’re gone
Couple people I know just got a week at NYNY, flying from Manchester direct in August for £460
Yeah they will come back in one form or another, it's just a case of being on the ball to catch them, and then being in a position to proceed (be that financially, with work, family etc)
Black Friday is on the horizon and there are often very good flight/holiday deals kicking about that weekend. Sounds like your mates got a very good deal!
I'm a travel agent so I spend an abnormal amount of time looking at all things travel, so I'll usually stumble across cheap flights rather than actively seek them out. Sometimes it's just the luck of the draw.