I went in to sell some old jewelery and Neil was a huge help. He didn't try to BS me, told me what they were paying and we came to an agreement. I walked out with enough cash to close on my new house and even had enough left over for a steak. All in all, if you want to talk straight about what you're selling and you've done your homework, not only will they not lowball you, they'll open an informative discussion with transparency to boot.