Europe - What's a decent winter airfare US-EU?

A group of friends is contemplating ringing in 2013 in Europe (weighing a few different options for cities - AMS, PRG, DUB, BER), but I have no idea what a decent fare is for this time of the year (late December - early January). I know the sub-$500 fares of years past probably won't re-appear despite my wishful thinking, especially during the holidays.

Right now there are decent fares ($600-$800, depending on US origin) on Aer Lingus. I'm very tempted to purchase, but I rarely do so far in advance. Is it worth waiting? More experienced thoughts welcome. I've only traveled ex-US during the summer, which taints my view of a good airfare deal.

Fares go down (significantly) on Dec.25 from what they are on Dec.24 most years.

I would qualify decent at $600 with a mileage-earning carrier, $500 with something like Air Transat or Icelandair.

$600 is very good. If you like the cities, dates, and times, I would book it.

anybody's guess. about 7-8 years ago, CO started selling iad-lhr rt tickets in F for $1200. a few years befire that, BA sold bwi-lhr tickets for $100 each way. somewhere in between, the engire industry jumped rt tatl to 7-800 for a while, that included over dec-jan.

most of the time, biz class fares drop big time in early nov, and stay down until after the first of the year.

most of the time, biz class fares drop big time in early nov, and stay down until after the first of the year.

What's the relevance of mentioning C/J fares to the OP when he/she is looking at whether $600 is a good price for a ticket? :confused:
TATL C/J fares with 60-day advance purchase this summer are running $2400-2600 in many markets. You may see slightly lower in the winter depending on the economy. Still way more than what the OP is looking for.