The Correct Focus
Here's a freelancing tip.
In the absence of clear-cut laws governing freelancing, even more so if you accept foreign customers,
in all my conversations with clients, I've always focused more on the value I give to them, rather than the salary, benefits or perks I can get from them.
For example, during meetings, I try to steer the conversation into what their expectations are from me and getting their feedback on my performance. Then after my meetings with them, my thoughts tend to what I can deliver for them above and beyond the expectations they set.
I rarely ever ask about salary, benefits or perks. In my experience, as long as they're satisfied, or more than satisfied with the quantity and quality I provide, those things will just follow.
In fact, they will follow up with what you're currently getting from them, on their own, if they see that you are service-oriented, hardworking and deliver great quality. Even clients who are assholes can't dismiss anyone who is of great value to their organization.
It should always start with having the clearest idea of your performance. Good and consistent performance will always be your leverage. The worst position you can find yourself in is you start to negotiate with them to have a higher salary, then it turns out they were not satisfied with your performance to begin with.
Of course, this is always tempered with being always on the lookout for red flags. In the first place, we should accept only fair and sensible employers.