Let's not forget that M4 Macs are meant to be coming with 16Gb RAM and the commensurate price increase.
Nobody knows about the price.
It's possible that Gurman et. al. have got industry leaks about the spec (which may have to be shared with key developers etc. ahead of launch) but the price will be a closely guarded commercially-sensitive secret until the launch or
very shortly before.
...and as I think I've said before (here or in other threads) if the price goes up it will be because Apple's marketing department thinks the market will bear a price increase, no other reason. These are high-margin goods where the retail price has little to do with the bill of materials. Not that Apple won't
also want to reduce the BOM to the minimum the market will tolerate, but we're rapidly reaching the point where 8GB SoCs will start to become uneconomical to manufacture as demand for such small chips falls (see: the stories about "8Gb" iPad Pros actually containing 12GB chips.
I don't think it would be wise to be penny pinching by only doing 2 full USB4/TB3 ports with an M4 chip which is capable of having 4.
Again - the 4 controllers is just people's guesswork from looking at photos of the M4 die. Having "binned" chips with two of those disabled to meet a price point is entirely feasible. Or, as I said before, the M4 design might have dropped the extra, non-USB4 PCIe/USB3/eDP lines that the previous chips appear to have had in favour of using one or more of the USB4 ports for internal I/O.
NB: on the M3 iMac the base model just has 2 TB4 ports while $200 extra gets you 2 more USB 3.2-only ports, a couple of GPU cores and a different power brick (with Ethernet). So, Apple are quite prepared to charge extra for even non-TB USB-C ports.
I wouldn't have thought that the modern Thunderbolt controller chips were that much more expensive - Titan Ridge was meant to have been about $10-15 for the Intel Macs if I recall.
That's $10-$15 (plus an extra chip on the board) that Apple won't spend if they don't have to.
FWIW, the Plugable brand powered USB 4 / Thunderbolt 4 hub I bought is only
US$129.95,
...whereas a USB 3.2 hub with 4 downstream USB-C plugs is
$40 - so, yes, TB4 stuff has come down in price a little bit, but it's still a hefty premium and
not worth it if you already have enough ports for displays and true TB peripherals and just want to connect more USB 3 devices.
I went back to compare with the m3 and m3 pro MacBook Pros and it seems that Apple only offer official thunderbolt 4 ports (3 of them) with m3 pro models and presumably m3 max.
I think that's
entirely down to TB4 certification requiring support for at least 2 external displays over Thunderbolt while the M1/2/3 only support two displays
in total and the internal displays in Macbooks use up one of those
. I'm not aware of any other way in which the Apple Silicon USB4 ports fall short of TB4.
The M1 was hard-wired to only support one display via thunderbolt - even the M1 Mini could only do 1 via TB and 1 via HDMI - so all the ports were "USB4 with Thunderbolt"
The M2 Mini, with no internal display,
could support two via Thunderbolt so its ports qualified as TB4 while the M2 Macbooks still used up one for the internal display and were stuck with "USB4 with Thunderbolt"
The M3 MacBooks got a software update that allowed two displays in Thunderbolt in "clamshell" mode when the internal display was disabled - either that was too big an "if" to qualify as TB4 or the software update came too late to get the ports re-certified.
