The most striking technology prices in a sale are frequently gone within minutes of opening. The scarcity is planned, and it is the reason the price could be offered at all.
The headline price is an advertising cost
A deeply discounted item at the top of a sale is bought as promotion. It draws attention to the event and gives the advertising something concrete to say.
Because it is funded from the marketing budget rather than expected to earn margin, the retailer limits how many units it is willing to sell at that level.
The allocation is therefore set by what the promotion is worth, not by what demand will be. Selling out is the intended outcome rather than a failure of forecasting.
Traffic is the actual product being bought
Shoppers who arrive for the headline item and miss it rarely leave empty-handed. They buy the next model up, or the accessories, or something unrelated they saw on the way.
Those secondary purchases carry normal margin, and in volume they comfortably cover the loss on the small number of discounted units.
This is why the loss-leading item is often placed deep in the store or requires an account, a queue or an app. The path to it is part of the design.
Specification tiering protects the range
The discounted model is frequently a lower configuration than the one most shoppers actually want: less storage, a smaller screen, an older processor generation.
That gap gives the sales conversation somewhere to go once the cheap units are gone, and the upgrade is presented as a small step from a price the shopper has already accepted.
Anchoring does the rest. A slightly higher price looks reasonable next to the advertised one, even where it is close to the ordinary price.
Automated buying compresses the window further
For popular technology, resale demand attracts software that monitors stock and completes checkout far faster than a person can.
Retailers respond with queues, account age requirements and purchase limits, which slow the tools without eliminating them.
The visible effect is a sell-out that feels impossibly fast, and a resale listing appearing shortly afterwards at a considerably higher price.
The rest of the sale is where the value sits
Mid-range items discounted moderately are usually stocked in depth, because they are expected to sell at those prices for the whole event.
Those prices tend to hold or improve as the sale runs, since the retailer's aim there is volume rather than a burst of publicity.
Ignoring the countdown at the top of the page and working through the middle of the range is the less dramatic and more reliable approach.