There may be several reasons why the Asus 30HX graphics card is cheaper.
First, it may be an older product that has been replaced by a new generation of graphics cards, so the price has dropped.
Second, possibly because the market is highly competitive, other brands have launched graphics cards with similar performance but lower prices, and Asus has lowered its prices in order to remain competitive.
In addition, possibly due to supply chain optimization, cost control and other factors, Asus is able to offer this graphics card at a lower price. In short, the lower price of the Asus 30HX May be due to a combination of factors.