> I'd rather work with a good and nice manager than have a 50% salary increase.

But as soon as you find a good job with a decent manager that pays 50% more, you are going to leave.

Actually the moment that you've received that offer with 50% salary increase you already lost some of your motivations even though you may not notice it immediately. And you are going to continue lose more of your motivations because you know that you can earn more.

I think Money is equally important to many other things mentioned here. But the thing about money is that it isn't the only thing that matters. If you don't fix other problems, money can only keep your employees as long as they can't find a replacement with similar pay scale. And even until then they are going to under-perform.

So Money is important. You can't keep good, motivated, high performing employees only with a good pay check. But you can't keep them without a good pay check either.