I don't have a strong preference between the two (I might be wrong not to).
Of course, that assumes both parties in the negotiation are rational and sophisticated. A typical developer is brilliant at designing software, absolutely terrible at understanding markets, and devastatingly introverted, and so is likely to lowball themselves. You will very rarely do much better than the first number you give. If you think you're not up to the challenge, putting the first number on the table may be a bad move. It depends.
What doesn't depend is your current salary. Everyone is going to ask for it. There's nothing wrong with asking. But don't cough it up.
"My current salary? Then out of curiosity, what do you currently pay your developers?"
I've never answered that, but that should be entertainingly confusing, if you're not in any particular need of the job and have a strong bargaining position. (Or if they're really cool people.)
Of course, that assumes both parties in the negotiation are rational and sophisticated. A typical developer is brilliant at designing software, absolutely terrible at understanding markets, and devastatingly introverted, and so is likely to lowball themselves. You will very rarely do much better than the first number you give. If you think you're not up to the challenge, putting the first number on the table may be a bad move. It depends.
What doesn't depend is your current salary. Everyone is going to ask for it. There's nothing wrong with asking. But don't cough it up.