I spent 2 months travelling in Europe every summer from aged 18 - 23 - usually interrailing, but not always. All the usual interrail destinations - France, Spain, Morocco, Switzerland, Italy, Greece, Turkey, Germany, Austria, Netherlands, Belgium, Denmark, Sweden etc. Did a few winter and summer seasons as a holiday rep in Europe and the States after that.
Took 18 months off to travel/work when I was 25/26 and went to South Africa, Namibia, Zimbabwe, Zambia, Botswana, Malawi, Tanzania, Kenya, Australia, Singapore, Indonesia, Thailand, Vietnam and Malaysia. After that it was just normal work holiday allowance length trips until I was 33 - managed 7 trips to India, Nepal, Russia, Poland, Estonia, Lithuania, Latvia, Ireland, Sweden again, Finland, Peru, Bolivia, Egypt, Tunisia, the States a few times, then I got made redundant and took off again. I did 6 months in Argentina, Chile, Brazil, New Zealand, Australia and Thailand on the way home.
Since then there has been less travelling - you asked in the OP about whether long haul travel would be expensive, but I see it more as being not very environmentally acceptable. Having said that, I go skiing twice a year in France, which isn't environmentally acceptable either! In the last 10 years I've had a child, so travel has been more limited. We've taken her to Turkey, Greece, Italy, France a lot. I've been to Spain, Estonia, Portugal, Greece again on my own. I took just her to Estonia when she was 4 and to Morocco when she was 8. My partner is very carbon conscious and wants to only travel by train from now on. He knows that I don't have the same level of concern about this. We're going on a 3 week train trip with child this summer to France, Italy and Sardinia., but we're flying to Turkey in October. I expect I'll go and meet my Estonian friend somewhere in Europe in September too.
I've also travelled lots with work in a previous career, but all to places already mentioned above and mostly in Europe. I once went to Sydney for 24 hours and to Cape Town for 3 days. I expect the days of that sort of travel are over.
My wish list: Senegal, Gambia, Togo, Benin, Ghana. Iceland, Norway, Mexico, Costa Rica, Sri Lanka. And I've missed Cambodia 4 times now while visiting Thailand and Vietnam more than once, I should probably go there too at some point.
I love thinking and talking about travelling...