While I do agree that HP is a very scummy + awful company, their pricing system is not worse than that of many other companies. Many many companies use an inflated listed price system in combination with very large discounts, often fixed discounts per customer.

There's several benefits to this. One of the biggest is that it allows their vendors to give nice "discounts" to entice ignorant customers. Ignorant people are more likely to buy a $2000 computer with 50% discount than a $1000 with 0% discount. And occasionally someone will come along and be scammed out of paying full listed price.

Inflating the list price is just very common and 50% is not even one of the worst offenders, just look at American health insurance prices for a much more egregious example. Construction building suppliers also systematically use it and "discounts" of 40 to 70% are common.