When to buy tickets
 

We will be going from atlanta to our son's wedding on Sept. 24th in Newcastle, England.
Should we book now or wait a bit?

Also, son will be traveling back with his fiance on August 15 with on one-way ticket. Checked price yesterday - very high. Likely to go down?

Aer Lingus usually has cheaper one way tickets.

When do you plan to come back. I usually recommend three months ahead of time for international and five weeks ahead for domestic.

In Florida, September is the worst time of the year for restaurants as the older people are traveling in Europe. But the kids will be back in school if you don't need to return until September--perhaps a price break.

www.kayak.com has an option that allows you do check days three before or after your selected date to see if it could be cheaper on another day. This is also helpful when an airline only flies that route five or six days a week.

Looks like London, Manchester, and Glasgow have lower prices than Newcastle for Aug 15. Do you have miles to get a one-way ticket (e.g. use United miles from London)? Continental miles that can be transferred to United for a one-way award? If you have Delta miles, do they offer one-way awards?

My wife and I just picked up 80000 AAdvantage miles

aa.com got 2 free flights RT to Europe.

You have time to do something like that.

They usually drop prices in late Aurgust for Sept

monitor cheapoair.com kayak.com buzz

so personally might wait...