In most laptops you can remove the WiFi/Bluetooth card if you are ok with a permanent solution.

I literally just bought a framework 13 laptop and was poking around in it (because it’s a repairable laptop). It 100% has a removable wireless card, and I was surprised because I assumed those were all soldered onto main boards these days.

https://guides.frame.work/Guide/WiFi+Replacement+Guide/96

Just take out the wifi module. If you need wifi just use a USB adapter. That's your kill switch.

If you're running Linux, another solution would be simply blacklisting the WiFi driver from the kernel.
It's a software solution, but I fail to see any downside to it.

You can open up just about anything and unplug it

just get an older thinkpad and remove the wifi/bt module

I know you are looking for new but I know in my ThinkPad T480 the wireless card can be easily removed. It's not that old, 2018. Still runs modern Linux wonderfully...and is well supported. It would be more than enough to do what you wanted. EBay is a good place to find them.

why hardware kill switch? with Linux u can disable them and unload the associated kernel modules. is that not good enough for u?

The pinebook's privacy switches (for WiFi/BT, camera, and microphone) operate at the firmware level, the operating system has no control over them

https://wiki.pine64.org/wiki/Pinebook_Pro#Privacy_Switches

The keyboard operates on firmware independent of the operating system. It detects if one of the F10, F11 or F12 keys is pressed in combination with the Pine key for 3 seconds. Doing so disables power to the appropriate peripheral, thereby disabling it. This has the same effect as cutting off the power to each peripheral with a physical switch. This implementation is very secure, since the firmware that determines whether a peripheral gets power is not part of the Pinebook Pro’s operating system. So the power state value for each peripheral cannot be overridden or accessed from the operating system. The power state setting for each peripheral is stored across reboots inside the keyboard's firmware flash memory.

Some ThinkPads have killswitches.

As does the Framework laptops i think... ~~the former can be bought second hand fairly easily~~.

Well, most laptops have removable WiFi cards, ~~but if you want to go the extra mile you could try an early-2000s or late-90s ThinkPad (from back when they were made by IBM).~~

Disabling it at bios level does not suit your case?

I think looking at business/enterprise models would give you the best luck, as some of them should use a PCIe Wifi/BT card so it can be easily upgraded, and you would be able to remove that.

Notebookcheck.net often has images of a teardown in their reviews where you can see if it has a removable wireless card.

I can’t help you with the budget. That’s not enough money to buy a laptop new with that particular functionality.

If you can tolerate getting something older (and your described use case doesn’t sound like it would prohibit an older device!), thinkpads, MacBooks and the like almost always have removable wireless and Bluetooth modules.

These older devices are often a better choice than newer ones because they’re repairable and parts are plentiful and inexpensive. You will be much happier spending $200 on a used t480 or 2012 mbp than you will buying a new computer at that price.

You need to yank the antennas too if you’re really a paranoiac, but if a killswitch would be enough then you’re very clearly not that person.

Nitrokey sells laptops that let you remove all wireless connectivity. They are also Qubes OS certified.

Come to think of it, would it also be possible to remove (or at least physically disconnect on motherboard) microphone and camera from an ideapad?

why do you want a new laptop? you get way better quality and performance for the same price with used ones

You can probably find something cheap from 1998.