Airfare craziness

I'm travelling to the USA soon for a conference so today I was arranging flights, you know that thing that used to take a travel agent, was lots of hassle and always left you frazzled and now you routinely do in 20 minutes on the internet.

I went to my preferred airline website and logged in and went to Multi-city planner. Put in my plan. Canberra to Sydney on day 1. Sydney to Dallas Fortworth on Day 1. Dallas to Detroit on Day 1. Coming back a week later Detroit to Dallas Day 5, Dallas to Sydney Day 5, Sydney to Canberra Day 7.
OK now to see what flights it could find.
Error. Sorry you can't have three segments on the same day. Since I'm flying back in time to the USA I arrive in Dallas 20 minutes after I leave Sydney after being on the plane for 14+ hours and then I want to leave Dallas on the same day. Sorry. Can't do that.
So I went to a flight comparison site. One of them couldn't do the dates I wanted and the other suggested two airlines, my preferred carrier and another I am less fond of. When I had a look at the dates etc, I couldn't get it to come out to an estimate that I had made a week ago so I put that aside and went back to my preferred carrier website.

OK. Let's get an idea of the cost. Drop the Canberra to Sydney leg. Try again. Play with the dates a little and it suggests $1,820. OK that looks acceptable I'll work out what to do about the Canberra leg later. Move on to the next page of the booking process. Price changes from $1,820 to $2,460. WTF!
Call the airline, wait 15 minutes on hold. Speak to a very nice person who tells me they can ticket me for $2,790. Explain that I can do better through the internet (their site) and told sorry the only way you can get a price like that is to book it through the internet. OK. Thanks anyway.
Go back and try a simple Return trip. Canberra to Detroit. Sure I can do that. It selected exactly the same flights as I would have selected on the multi-city planner and was ready to charge me $4,700 EACH WAY.
Really WTF!!
Go back and try Canberra to Dallas to Detroit to Dallas to Sydney to Canberra. Some flexibility on the dates. After a bit of back and forth and testing I can book the flights for $1,871 if I leave Dallas on the Saturday instead of Thursday or Friday. Or I can pay $2,500 if I leave on the Thursday. It turns out that with accommodation and sundry meals it is still going to be $250 cheaper for me to spend another two nights in Detroit and fly back on Saturday.
Bottom line is if I wasn't a little careful I could have paid anything up to $9,500 for exactly the same flights and class (economy) as I have now paid $1,900 including credit card surcharge!.

So while the simple travel plans are now much simpler to arrange with the interwebs some slightly more complex plans are still apt to get you a bit frazzled.

The bonus is I get to fly on the A380 from LA to Sydney so that will be a new experience for me.