I am genuinely confused as to how to answer this question: as this is a position that is hiring globally, it seems that applicants who live in regions where the cost of living is substantially lower can of course in turn list their salary expectations as much lower.
Logically, global-hire positions then seem to me to be a race to the bottom. If I list my salary expectations as the equivalent of $20 an hour, an equally-qualified candidate who lists theirs as $10 an hour will of course logically get the job instead. So what do you do in such a scenario? Offer to work for practically nothing, or risk not getting hired because someone else is willing to work for less?
Furthermore, if someone from cheap country is truly as good as someone from developed country at doing the same job then it is undesirable for them to sell their work too cheaply (let's ignore clickworkers here - we're talking about skilled knowledge work). If quality is there, they want to sell it at marginally lower price. Therefore global competition for skilled work does not necessarily cause race to the bottom - cost of labour will converge to some globally mediocre level long-term. It may go down in the first world, but will go up in cheaper places. Employers are likely to still find it worthwhile to pay more for local candidates work ceteris paribus due to cultural affinity advantage that is difficult to surpass for someone from abroad.
Consider Upwork. There's masses of people spamming the platform with incoherent ramblings about how good they are at doing something real cheap (and still struggling to get enough work), but on the other hand there are people making six figure yearly amounts. That would not be the case if global competition always made the price go down to third world levels.
Just say the amount you feel is fair to ask for what you can do and would the worthwhile for you.
The company will get to pay a lower wage if and when they find another candidate they like who's willing to take it. For the moment they have you; they may or may not have someone else.
Their strategy could net them someone with your skills for less, but playing that game comes with risk and costs them time and money in the short term even if they win. If you reduce your bid because they might find someone cheaper, you guarantee they get their best-case outcome at no cost with zero risk, at your expense.
They're hoping you'll assume the market doesn't bear your price. Maybe it does, maybe it doesn't. You don't find out unless you ask.
[1] In order to have this info, you should either interview semi-regularly or at least have a network of colleagues in similar roles who are sharing market info with you.
1. If you have strong negotiation position - just state your expectations and make sure they are really high and satisfy you (do you research)
2. Any other case - never share your expectations until the end of interview process and untilyou know what’s the salary band/level they estimated you. Then negotiate up to max of that band (based on your research, again)
Most companies are still going to hire locally and so better to focus on just getting one of those local jobs.
The alternative is to do the kind of work very few else can do. For example, there are a lot of people who can take a ticket and code a solution that functions. There are substantially fewer people who can take a vague idea and code a solution that scales, both in terms of performance and in terms of additional functionality.