This is what happened in my last negotiation, where $X was a 30%-ish raise. They didn't bat an eye, and made an offer of exactly $X. I asked them, "Could we make that $(X + .06*X) and they did.
I keep raising my rates 30% every time someone asks, mainly because I don't want to take on more work, but apparently people don't mind, so I keep getting more work... Oh, the humanity.
