According to this Chinese military expert, China would need at least 20 x Type 075 to satisfy its future maritime defense requirements. He also said that the helicopter carriers, while big by displacement, are actually much more cheaper to produce than destroyers.
This is actually true for many other LHDs as well. The French Mistral for example, costs around 450 million euros while their FREMM frigate costs around 600 million euros. The US Wasp costs around 1 billion dollars while an Arleigh Burke III costs more than twice as much.