Many thanks for those tips. Based on my searches so far, it seems fair to return some knowledge....
The Expedia search engine seems very flexible, but the ITA site gives some useful pointers that I haven't seen elsewhere - long layover, prop flights, etc.
One thing I've found so far is that not every search engine seems to get access to the same flight options. The tentative itinerary I'd mapped out was Glasgow to Chicago to Las Vegas to Boston then back to Glasgow.
Knowing that AA do a direct Glasgow to Chicago flight during the summer season, I thought that was the obvious choice, but sometimes I was getting offered GLA-LGW/LHR-ORD with AA rather than direct, yet other engines were giving me the direct option.
So far Expedia has come up with the best results of the multi supplier engines - on the dates I was looking at (in September) it gave me:
GLA-ORD (via LHR)
ORD-LAS (via LAX)
LAS-BOS (non stop)
BOS-GLA (via ORD)
all on AA for £612. Which I thought was excellent, but with more connections than I expected.
So it occurred to me to try the AA website directly, which gave me:
GLA-ORD (non stop)
ORD-LAS (non stop)
LAS-BOS (non stop)
BOS-GLA (via ORD)
all on AA for £599.30. I nearly booked the tickets on the spot!!! Oohhh I do hope we can get the holiday plans sorted out quickly!
I did look at the open jaw combined with budget airlines options, but the open jaw tickets were generally in excess of £500 on their own, so even though some of the budget flights looked like great value, the sums still didn't stack up.
So, thanks again for your help. I hope my info is useful to others too.
