M4 vs M6 Mac mini: which to buy (the 'clearance' math)

I've been watching the Mac mini listings since Apple quietly launched the M6 model on 25 August, and I have to tell you what I found this morning: the "clearance" M4 is currently the worst-priced Mac mini on the page. That's not a hot take, it's arithmetic. The deal headlines from earlier this month were real when they were written. They just aren't the price you'll see today, and one of them probably never meant what people thought it meant.

Prime Big Deal Days runs on 6–7 October, so a lot of people are about to search for a cheap M4 thinking the old model is the bargain. Here's the math first, then the thresholds to check yourself on sale day, because Amazon prices move daily and I'd rather give you the rule than a number that's stale by tomorrow.

What the prices actually are today (25 September 2026)

I checked every listing myself this morning, with Amazon set to a US delivery address (New York, 10001) and Apple's US store. Here's what was live, including who is actually selling each unit, because on Amazon that's where the story is.

How the M4 went from $599 to 'more than the new one'

It helps to know how we got here. In May 2026 Apple dropped the $599 entry Mac mini and moved the starting price to $799, a change MacRumors reported on 1 May and tied to the same memory shortage that's pushing up everything with RAM in it. Then the M6 arrived at $899. Once Apple stopped selling the M4, the remaining new stock went to resellers, and they price against the old list prices, not against the M6.

So the old intuition, "last year's model gets cheap when the new one lands", held for a couple of weeks and then stopped holding. On 23 September MacRumors logged the M6 at $879.99 on Amazon during its launch discount; by this morning it was back to $899. Both machines are moving. The gap between them is what matters, and right now it's the wrong way round for the M4.

What you actually give up with the M4

The spec I care most about is memory bandwidth. Apple lists up to 170GB/s for the M6; the base M4 is about 120GB/s, the figure we used in our M4 vs M4 Pro local-AI breakdown. On paper that's roughly 40% more. For everyday use you won't feel that in Safari. You will feel it if you run local AI models, because text generation speed tracks memory bandwidth closely. I'm not going to invent a tokens-per-second number here; nobody's published a like-for-like comparison I trust yet. The direction is not in doubt, though. (If gpt-oss-20b is the model you have in mind, I worked through what it needs on a 16GB vs 24GB Mac mini.)

What doesn't change: both top out at 32GB of memory, so if you want to run bigger models, neither base chip is the answer. That's M5 Pro territory ($1,699 at Apple) or a different kind of machine. And memory is soldered on both, so buy the amount you'll need on day one.

The thresholds: when the M4 wins

Here's the part to screenshot before 6 October. I'm not asserting what Amazon will charge on sale day; I'm giving you the prices at which I'd switch my answer.

• New M4 16GB/256GB under ~$700, sold by Amazon.com or Apple: buy it. At about $200 below the M6 you're paying fair money for the older bandwidth.
• Refurb M4 16GB/512GB at $849 (Apple): a fair buy if you need 512GB and you're not running local AI. You'd pay $1,069 for the same memory and storage on the M6 at Amazon today.
• M6 dips below $879.99 during Prime Big Deal Days: that beats its own launch-week price, so buy the M6 and don't look back.
• Anything used or from an unknown third-party seller near $840: skip. For $59 more you get a new M6 with a full warranty from Amazon.

If you want the M4 anyway, and the thresholds above say it's time, the Amazon listing is below. Check the seller line and the condition label before you add it to your cart. Apple's refurbished stock is on Apple's refurbished Mac mini page, and it moves fast.

Who should still buy the M4

Shopping more than one Apple product this week? I did the same maths on the AirPods 4 "price drop" vs AirPods 5, and the pattern is the same: the older model got more expensive once Amazon stopped stocking it.

Building a PC instead? The same shortage that pushed the Mac mini's price up is behind the RAM bill. I've put the dated price record and the numbers to buy at in RAM prices: Prime Day or Black Friday?, and priced a whole budget platform both ways in DDR4 vs DDR5 for a budget build.