The first step in buying a piece of jewelry is to trust your jeweler. You must find someone that you are comfortable with and that you feel confident buying from. Everyone is looking to make a quick buck and unfortunately there are jewelry stores out there with an extreme retail markup. Not only is there this markup, you may not be getting the quality that you are paying for.
Just because someone says that a piece of gold is a certain carat, or a diamond is of a certain class, double check. Have him or her test the gold to prove to you that it is actually that carat, and make sure that your diamond comes with a certificate. Working in the gold industry for a long time, I have seen many horror stories with gold that is marked 18k and is not. Or even with stones that were sold as diamonds and are worthless cubic zirconia.
Not only is it important to trust your jeweler when buying but also in case of damage. What happens if you lose one of the side small stones off a ring and need to get it replaced? 99% of the time you are going to have to leave it with the jeweler for repair. If you don’t trust him or her, you are not going to want to leave your jewelry with them.
It is important to build a relationship for your own comfort. Not only that, but if you continue to go back to the same jeweler, maybe they will work with you on the price.
Hope this helped. Happy shopping.