I guess it would feel more fair if the deal explicitly contained a note like "and if you move elsewhere for whichever reason, we'll adjust the salary so that you have at least as good a standard of living as you do now".
I guess it would feel more fair if the deal explicitly contained a note like "and if you move elsewhere for whichever reason, we'll adjust the salary so that you have at least as good a standard of living as you do now".