The honest answer is that it depends on four things, and only one of them is the model. People tend to assume the generation is the whole story, then get surprised when a well-kept S23 Ultra is worth more than a battered S25.
This guide covers what genuinely moves the price in the South African market, in rough order of how much each one matters.
1. Which model, and how close it is to the current one
This is the biggest single factor, but it does not work the way most people expect. Value does not decline smoothly with age. It falls in steps, and the steps happen at Samsung's launch events.
The largest single drop for any Galaxy is the few weeks around its successor being announced. The second largest is when it becomes two generations old, because that is the point where it stops being the phone people want and becomes the phone people settle for. Between those events, prices drift down gently rather than falling.
Samsung now runs two significant launches a year, the S series early and the foldables mid-year, which means two repricing events rather than one. That makes holding on to a phone you already intend to sell more expensive than it used to be.
There is also a within-generation split that catches people out. The Ultra is not a trim level, it is a different phone with a different buyer, and the gap between an Ultra and a standard model of the same year is wider second-hand than it was at retail.
2. The screen, which on a Samsung is the expensive part
Samsung makes the best phone displays in the world and charges accordingly to replace them. That is excellent when the screen is perfect and painful when it is not, and it makes screen condition the second biggest factor in a Galaxy's resale value by a distance.
Three separate things live under this heading and they are worth distinguishing, because people tend to lump them together and then describe their phone inaccurately.
- Cracked glass, which is impact damage and the obvious one
- The vertical green line, a known AMOLED failure that appears without anybody dropping anything, often after an update
- Burn-in, where years of the same status bar or always-on display leave a faint permanent ghost
3. Battery health, which matters from about year two
For the first eighteen months or so, nobody asks. After that it becomes the first question a second-hand buyer has, because a phone that does not last a day is a phone with a repair bill attached.
Samsung now shows this directly under Settings, Battery, Battery health. Check the actual figure rather than estimating from how the phone feels. Guessing high is the single most common reason an offer changes after testing, and it is entirely avoidable.
Above 90% is unremarkable. Between 85% and 90% is normal wear. Below 85% is where a buyer starts budgeting for a replacement and the price reflects it.
4. What is in the box, and what is missing from it
Samsung stopped including a charger years ago, so the box and the cable are what is left, and neither is worth a great deal on its own. Together they are worth having.
The exception is the S Pen, which is worth considerably more than people assume and is the single most commonly missing item on any Ultra or Note. It lives inside the phone until the one day it does not, and by year two a large share of them are gone.
On a Galaxy Tab the equivalent is the Book Cover Keyboard, which is worth real money and is almost always in a cupboard rather than in the box.
Getting your actual offer
Everything above tells you roughly where your Galaxy sits. Your actual offer depends on the exact phone: the model and storage, the screen, the battery and whether the S Pen is there. The calculator asks about each of those and gives you an offer in about a minute, with no account and no obligation.
What the asking prices online are actually telling you
The classifieds are the usual reference point and they are a poor one. What you see there is what people are asking, not what anybody paid, and the two are separated by weeks of the listing sitting there before the price comes down.
The other half of the difference is what the asking price is buying. A private sale at a higher price involves meeting a stranger, carrying the risk of a fake transfer, having no recourse if they claim the phone was faulty a week later, and doing all of the admin yourself. Our offer is lower on purpose, and what the difference buys is certainty and a free courier.
Both are legitimate choices. What is not legitimate is comparing a buyback offer to an asking price as though they are the same kind of price.
The short version
Model and how recent it is does most of the work, screen condition does most of the rest, battery health matters from about year two, and the S Pen is worth more than you think. Asking prices in the classifieds are not what anyone is paying. For your phone's actual offer, the calculator takes about a minute.