The difference between branded jewelry and no-name (with the exception of unique artist-created designs) is largely a matter of marketing and shopping experience. The quality of materials is different.
However, there is a difference in the amount of work you need to put in to custom jewelry. You need to know what is good and what is not, and judge between them. With branded jewelry, you can be lazy - you don't need to know the optimal table to depth ratio of a diamond or the other factors that determine diamond quality - the 4Cs have you covered. The branded companies also provide after market service, resale value and bragging rights.
However, there is a difference in the amount of work you need to put in to custom jewelry. You need to know what is good and what is not, and judge between them. With branded jewelry, you can be lazy - you don't need to know the optimal table to depth ratio of a diamond or the other factors that determine diamond quality - the 4Cs have you covered. The branded companies also provide after market service, resale value and bragging rights.