Originally Posted by
ss2000
I understand there are reasons why flight going from X to Y is much more expensive than going Y to X but why would X to Y roundtrip be vastly different than Y to X? (Some price differences I can understand due to demand, whatever).
Market forces. If you want to go from the US to Sri Lanka and then come back, the implication is that you live in the US and are going there for work or vacation. If you start in Sri Lanka the implication is that you live there. Typically as an American you have more money. Therefore the airlines have less incentive to low ball a price. But the other way around you're assumed to have less money. So the airlines need to price accordingly.
I have the same situation between SFO and BKK. I live in the US. But I have a long term visa for Thailand. So I can start my trips there and return to Thailand without visa worries and without airlines questioning my travel documents. So I pay just over $3,000 for a business R/T while the other direction is nearly $7,000.
Many airline sites check your IP address to make sure you are ordering from the correct country. Others make you change your home country manually. If they think you are playing a game, they'll void your ticket.
Don't try "nesting" tickets. (DFW/CMD returning a year later with a CMD/DFW/CMD ticket in between). They will catch that and void all your tickets.
If you happen to be in the wrong place when your ticket gets voided it's your problem, not theirs.