[tempestn]

There are definitely some good points here. As someone who has done a decent amount of negotiating on both sides, I will say that while it's true that even in a startup your boss won't much care if you negotiate... they might care if you mercilessly try to squeeze out every. last. drop. as described here - even if you do it unfailingly politely. In a situation where there only a handful of employees and you're reporting to the founder, they may actually care about that last 10k you squeezed out at the deadline. Probably not enough to withdraw the offer, but perhaps enough to put a bit of a damper on the future relationship. I'm not saying it's not something that could be overcome. If you really are a 'rockstar', it would probably be quickly forgotten. But still, there is some value to leaving a small amount on the table. Especially since you can always negotiate a raise if your performance is indeed excellent. (Although admittedly your current salary does always anchor that somewhat, so I'm certainly not recommending giving up a lot initially.)