Having just checked my internal drive, I find the bigger "sinners":
Just an aside to plug
Disk Inventory X as the best tool (& free) I've found for investigating what's eating your storage.... and, yup, it still works on a Studio with Monterey.
The OP is asking if he should buy 1TB or 2TB of internal storage, i.e. the additional cost is $400. All I am saying is that for a lot of photographers 1TB quickly runs out. I am one myself...
Question is, if you fill up 1TB that quickly, how long is an extra 1TB actually going to last?
Whereas that $400 will buy you between about 2TB (fastest SSDs) and 16TB (spinning rust) of external storage - depending on your need for speed (and you probably don't need bleeding-edge ultra fast SSDs unless you're going to be editing ultra-high-def video direct from them)... Or, since you're going to need external storage for archiving and backup
anyway put the cash towards a multi-drive external storage or NAS unit.
The big speed advantage of Apple's super-fast SSD comes from having your system, swap and temporary storage on it, and 1TB is fine for that.
Today, spinning rust is still the most affordable way of storing terabytes of data, so maybe start with that, but the odds are that, during the 3+ year life cycle of your Mac, SSD price/terabyte will drop and you'll want to upgrade your storage.
I also have no idea why someone who has purchased, and uses, Final Cut Pro X and Logic Pro X would keep iMovie and GarageBand on their computer.
...because the actual size of the apps and libraries is negligible alongside the size of the project files that you'll create with Logic or FCPX so it's not worth the inconvenience. Anyway, if you've started with iMovie or GarageBand you might have old projects in that format (yeah, you can import them into the "grown up" app but that's rarely seamless).
Exactly this. I paid a fair bit extra to get the SSD on my iMac because the default storage was a Fusion drive and I think it was worth every penny I paid for it.
Well, that's rather different, because the Fusion drive was a compromise from the days when more than about 128GB of SSD was far less affordable.
In 5 years, you won't care about the extra $400, but you may very well wish you had more internal storage.
Most people here could probably get their work done with a second-hand M1 Mini - so they've already applied your logic several times over to get as far as a Mac Studio - you have to draw the line somewhere on the road to an 8TB Studio Ultra and a second mortgage. The point of discussions like this is to help people decide where they, personally, want to get off the ladder.
Of the various decisions you have to make, storage is the least critical because it's the easiest to rectify with external storage. A couple of aliases on your desktop, say redirecting Documents to the external drive - and it's pretty transparent. RAM, CPU and GPU cores are less easily rectified...
I'd still say that it's only worth going over 1TB if you have a clear use case for needing more (and some people
will). However, if you're continually accumulating huge video/graphics/audio files you'll soon exhaust
any affordable level of internal storage and need to work out a storage/backup/archive strategy using external drives/NAS/whatever.
...and don't obsess with sustained transfer speed benchmarks unless you're worried about how many simultaneous ProRes streams you can handle!