Diamond promise rings are not as expensive as a diamond engagement ring because the diamonds used in them are much smaller when compared to engagement rings. Many diamond promise rings can be customized. You can pick from different types of gold to different colors of diamonds. It all comes down to what the person who you are giving it to likes! Diamond promise rings typically run around $200 for a ring with a very small diamond to over $1,000 for a ring with a diamond that is about the size of a quarter carat or more. You can purchase diamond promise rings that resemble a diamond
engagement ring, however these diamond promise rings usually cost a bit more.