Consider
Apple refurbished. Note that this is different than refurbished from Amazon, Best Buy, etc. Apple refurbished are like-new quality direct from Apple with the same warranty as new, but a 15-20% discount. Available configurations change daily, sometimes several times a day, so it's good to decide the specs or range of specs you need, then check back often until the machine you want is available. At that point, buy immediately. They can go out of stock within hours.
Agree with Allen_Wentz: having plenty of memory at the get-go is going to matter
far more than having the absolute latest and greatest processor. Respectfully, anyone who would lobby for you to
only consider a top of the line, brand-new M4 are giving you FOMO advice, not "I use my computer to do work" advice. For video editing + Logic, any modern, Apple Silicon-based Mac will work well: M2 Max or M3 Max, with plenty of memory and as much storage as you feel is important to have internally. I'd even consider a first-generation M1 Max if the price and specs were right (I still use an M1 Pro-based 16" MacBook Pro to run my business as a graphic artist/editorial designer. It doesn't let me down in the slightest. But I realize the needs of video editors are unique and that's not my wheelhouse).
But speaking of storage, general advice you can take or leave: Don't be so hung up on maximum internal storage unless portability is paramount above all other considerations, including budget. You're going to pay a huge premium for that 8TB storage tier, regardless the model, because Apple's storage pricing is (like most OEMs) completely insane. 2–4TB is the value sweetspot. Augment this as your needs dictate with speedy externals.