I have the M3 Max Macbook Pro 36GB/1TB/30 core. Right now, Apple is giving $1200 trade-in and I am looking at grabbing the M4 Max 64GB/4TB/40 core before Apple lowers my tradein value or worse, changes the design of the M5 (less likely) or M6 (guaranteed). My M3 Max runs fine, I don’t really need the M4 Max blah blah, but this is a case of future proofing while the odds are in my favor. I hate my 1TB drive.
Am I stupid for thinking this way now or should I wait?
I wouldn’t do it just for that reason. Your new M4 laptop would see a bigger drop in trade-in value than the current M3 over the next year.
I am thinking, this would be the last one though. no more trade-ins.
Don’t do it! Future-proofing is a myth. As long as your current computer gets the job done (and apparently your M3 MBP does) there is no economy in trading it in. If you wait two years for the M6, that’s two more years of usage (double the usage) of you M3, more than making up for the loss in trade-in value, and you end up with an M6 instead of a two year old M4.
Moving away to be a mountain-top hermit?
There is never a “last one” 
Katie
That’s all you need right there.
It’s like a stone in your shoe.
Hate is a strong word, but if you can afford to remove a little something you “hate” in your life … go for it.
Wait … did David hack your account and write for you?
(How many times have we heard from David that the next thing will be the last, or nearly the last, or cure cancer.)
You won’t barely be able to notice a difference, so this would be a waste of thousands of dollars. As others state, future proofing is a myth, if your machine is fine for your needs don’t waste a lot of money!! In five years you’ll need an upgrade anyway to keep up with new tech.
Grab an external SSD for $200 and enjoy.
+1
Like others have advised, wait. Don’t let your emotions (the elephant) drive a decision that your reason (the rider) merely tries to justify: “The mind is divided, like a rider on an elephant, and the rider’s job is to serve the elephant.”* 
Ok thanks everyone. I have gotten a grip on my technolust for now so I will wait.
This is the fear that drives me. I passed on the 2015 Macbook Pro and waited. I was rewarded with the janky butterfly keybooard and no ports of 2017. I am really worried that if I don’t get the current model, Apple is going to ruin the Macbook Pro again.
Anything is possible; every company has its duds. But I don’t think this will happen. Over the last several years, the updates to the Mac have been fantastic. I believe you can have confidence that Macs going forward will continue to be excellent: who knows, perhaps they’ll release a touch-screen or “convertible” Mac in the not-too-distant future.
If you hate the M6 design and want to upgrade to the last “good” one, grab a refurbished M5 at that point. You’ll save even more money!
If you genuinely need more storage though, I get upgrading now.
I’m running a M1 Max since 2022, and there’s 0 reason so far to upgrade (I’m a 3d artist and use it to its full potential with blender/Zbrush etc, the really resource heavy stuff). What’s the point of going 1 gen forward(other than the ssd upgrade, which you can rectify with a 100-300 dollars portable external ssd)? 1200 seems unreasonably low for a machine such as yours.
Apple knocked it out of the park with Apple silicon, any m-series max processor is sure to be fine for at least another 5 years in my estimation, m3 even more so.
And if he loves the M6 design, he can wait 6 months more, grab a refurbished M6 and also save more money!
I’d consider whether you need more than 1 TB on your device itself. If you’re hitting drive limitations for things that absolutely can’t be offloaded, that might justify an upgrade.
But practically, I think of storage as two categories. There’s stuff I absolutely have to have with me at all times, and stuff that’s fine to have on an external drive (possibly having to wait until I get back home to access).
External drives are relatively cheap. Even cheaper if you’re fine with a spinning disk.
There’s another solution you can roll - a NAS (grabbed a UGreen 2-bay NAS a few weeks ago, a great experience so far). Like your own iCloud in simple terms, you can access your files from anywhere and from any device.
It’s admittedly a bit more fiddly than an external hard drive, but you can have a versatile setup of 16± TB under 600-700$ without having to pay those crazy monthly fees (like the 2tb iCloud plan at 10$/m), which also has the added benefit of serving as your media server through plex/jellyfin etc.
Your are then not forced to dish out for a bigger hard drive every time you think to upgrade your devices.
A win-win, imo, if you’re willing to tinker a bit with it.
I bought a QNAP DAS. Like a NAS, except you have to plug it into a computer like an external drive. Much less fiddling, same great storage capacity. I think I was out $1000 for 24 TB of RAID 5 storage. I have it on a Mac Mini. If I didn’t have the Mini, I’d probably have gotten a NAS. 
M6 redesign there is some much speculation, that we can’t tell what will change. If you don’t like the M6, the M7/8 will fix most of the problems.
I upgrade an M1 Touch Bar “Pro” to an M3Max because I ran out of storage. I paid for 64GB RAM and 4TB SSD. I got a noticeable perf bump. My goal is to wait until the M8 generation before upgrading.
So I would only upgrade if the SSD or RAM are really limiting you.
+1
I’m old-fashioned. I wouldn’t be comfortable storing important data on a terabyte of nonredundant disc storage. I would only have that much internal storage if I needed it for editing video, etc.