Insisting on getting a branded diamond is one thing that is sure to strain your budget. It is easy for most people to simply move on to a non-branded, which requires them to spend less, but there are some significantly valid points against doing that.
Branded diamonds extract a premium as part of the price you pay for them, but this is rarely a waste. There is the assurance that the stone you are buying came from a line of diamonds, which adhere to specific cut parameters. The benefit of seeking out a top luxury brand is that the premium would not be as high as otherwise. Some of these have unique value adding policies that even the best non-brand vendors fail to offer. This may include the replacement of one of your bridge diamond rings a handful of years after you originally bought it.
The main thing that makes luxury brands far from advisable for an average buyer, is the steep prices they place on their products. However, there is also the fact that many of them do not reveal sufficient information about the cut of the stone, which is something many diamond enthusiasts cannot abide. Rockher achieves the best of both world by guaranteeing the quality of diamond and asserting their own branding; Rockher jewels are definitely the premium among branded diamonds.