The message that you are “almost” at a free-shipping threshold changes the question at checkout. Instead of asking whether the original purchase is worthwhile, it invites you to spend more. Pause and compare the new basket with the one you intended to buy.
First, establish the actual delivery charge for your address. Then read the threshold conditions. Some offers apply only to eligible products, a particular seller or a selected delivery method. A basket can exceed a headline minimum without qualifying. Check the result after entering your destination, and do not assume that adding any item will remove the charge.
The basic comparison is straightforward: extra spending versus delivery cost removed. If the additional product costs more than the freight you avoid and you have no use for it, the revised order is more expensive. Calling the delivery free does not change that. Also check whether the addition creates another shipment, changes the arrival estimate or introduces a separate seller's delivery conditions.
A genuinely planned purchase deserves a different assessment. Perhaps you were already going to replace a specific notebook next week, and the exact suitable notebook is available. Compare buying it now with buying it separately later. Include the total and whether the earlier purchase changes anything practical. Do not assign an imaginary future delivery charge simply to make the combined basket look better.
For consumable items, think about storage and realistic use. A spare that you will use within a sensible period can be useful; several unfamiliar products are a different proposition. Check that the format, size and specification are already known to work. Buying a large quantity merely because the remaining threshold is large transfers the problem from checkout to your cupboard.
Consider a hypothetical order with a modest delivery charge and an accessory that costs considerably more. Removing freight by adding the accessory increases today's spending. If the accessory was not on your purchase list, keep the original order or compare another merchant. If it was planned, compare the complete two-item basket rather than treating the accessory as a device for earning a benefit.
Review the final basket once more after any edit. Confirm the charge actually disappeared, that the product variation remains correct and that no unnecessary quantity has been added. Save the checkout summary if you proceed. The useful outcome is an appropriate order at an acceptable total, whether the receipt labels part of that total as shipping or includes delivery in another way.