I want to get a 3% discount on buying 500 BTC.
Sir, please don't believe anybody here except your nearest and close men. Because as it is big deal you may chance to lose your money. Third party may fall you in problem with frud so that be careful before deal any third party whom you did not seen ever. Best of luck.
Thanks.
Better do personal meet up in a popular but still secured place. Check the real identity of person you'll be meeting. Have middleman and check their backgrounds. Much better if your middleman is someone you know too personally or referred from someone you know. It's quite hard to transact if you're not going to meet that person.