Be prepared to walk away without what you set out to buy. You cannot be in a negotiating position really if you cannot actually take no for an answer, even if t

Be prepared to walk away without what you set out to buy. You cannot be in a negotiating position really if you cannot actually take no for an answer, even if they don't know it. If someone can do it, they will do it, unless you give them a reason to not want to, for example by insulting them in some way. Keep it light, keep it business, always be ready to accept the fact that an agreement can't be made, and try to work out a deal that you're happy with.