During the first phone interview from an HR recruiter, she gave brief two sentence introduction. Then, immediately asked for my current compensation. I explained that I prefer not to disclose that, yet. But, asked what is their starting range. She wouldn't tell me, but insisted on me disclosing my current salary. I again declined. She asked, "why?" I explained that the recruiter told me the starting range (and, I told her those numbers) and if that was accurate then it was an acceptable amount for me to do the screening interview; and I'd be happy to disclose my number in the future. (also, we all know that a good sales person doesn't give away their negotiating power in the first 30 seconds). She said that the base & commission is NON-Negotiable, and she CANNOT proceed with the phone interview unless I am willing to give her my current salary. I asked her, "Why?" And, she explained that the hiring manager doesn't want to waste his time with someone who is already making a lot more money, because they probably would not accept the position. I agreed and said that the recruiter's estimates are fine for me. She said again that she CANNOT proceed with the phone interview unless I am willing to give her my current salary. I said that maybe this isn't a good fit.
BTW: the recruiters estimates were VERY LOW: $55k base; $130 total at plan.