The thing that causes the price of a newly introduced product to plummet is the introduction of a newer product with better features.
It is possible to maintain the premium price unless and until the product becomes technically obsolete.
That means that a manufacturer must do three things:
1. Delay obsolescence as long as possible. Don't introduce the next generation product until either the market for the current generation has become saturated and a new product is needed to induce customers to replace the last product (this is a very popular trick with suppliers of technology-based products), or until the competition is about to introduce their newer, better, faster, sexier product.
2. Set the introductory prices as high as you can get away with so as to maximize the revenue during the early days.
3. Automate manufacturing to make production cost as low as possible.
Semiconductor manufacturers have one other trick. When the new product comes along, they then sell a license to manufacture the old product to a competitor (usually, someone in Asia) who can make it at an even lower cost. That does two things. First, it maintains a viable presence of that older product in the market so that the newer product 'looks' better by comparison, thereby justifying the premium price for the new product. Second, it maintains a revenue stream for the older product that further enhances its life-cycle profitability.