Diamond prices, like all other products, are driven by supply and demand. Particularily in the jewellery industry, the demand is the strongest driver of prices, as diamond manufacturers have almost always a possibility to choose the diamond shape. That choice will be driven by demand, as a polisher wants to create a diamond that can be sold as easily as possible.
Historically, the round brilliant diamonds were actually more difficult to polish as it was hard to keep a perfect or near perfect round shape.
But today, it's easier to polish a round diamond thanks to advanced machinery that allow manufacturers to cut a perfect round diamond. And consumer demand continues to drift towards round brilliant diamonds, so these diamonds sell at a considerable premium over non-round diamonds like oval, emerald and princess.
When it comes to diamond shape, it mostly a matter of taste and if you like a cushion-cut diamonds, for example, you will be able to buy a bigger/better diamond for the same price, if compared to purchasing a round diamond.
Soon at Masters of Light, you will be able to search for ideal cut perfect Hearts and Arrows - round diamonds with maximum brilliance and perfect symmetry. Because more important than the shape, the cut must always be as good as possible if you want your diamond to shine.