I am a slow traveller, I like to spend a few months in each place though sometimes that extends. For example, I moved to Budapest for 3 months but stayed for 18 months.
I’d budget $600 for an average one way trip economy and $1500 club class or better. If you shop around you can get pretty much anywhere for that price assuming you miss any seasonal high points like Easter or big holiday periods.
As for lowering the budgets, I wouldn’t know. My philosophy is to always earn more, rather than spend less. Life is all about experiences and for me, I’d prefer to put in a few extra hours a week to generate another sale or win a new project rather than scrimp on a cheap ticket and spend the same time stuck in a crappy transit lounge only to be cramped on a long haul, multi-stop flight to nominally save a few hundred bucks.
You can make more money easier than you can get back the time wasted on that kind of trip. And that’s before you factor in the stress and recovery time afterwards.