Of course not. The idea was that you'd get a base price from the ad, then call Dell's 1-800 number to order and customize the system. That way you didn't have to waste time haggling with salesdroids if the price was 10x what you could afford.
They didn't just "tell him," they laughed their heads off at him. Advertising prices and selling direct Just Was Not Done. Until it was, leaving a trail of bankrupt competitors that looked like that road in Iraq.
but they do generally have a price. Even if it's the super-high no-one-should-actually-pay-this price, it really helps with evaluating whether something should even be on the list to contact sales about.
All prices anywhere are "just made up". It's cost + taxes + profit margin you want to make on this deal. The market elasticity determines how often you want to move that price up or down.