I am wondering if any basic headlamps are equipped with a simple on/off switch as opposed to cycling through the various modes?
thanks
Yes but it varies depending on price range
What varies?
Any recommendations for a budget light of this type?
The switch on a single-mode light is the same as the switch on a multi-mode (or level) light; is that what you're looking for instead, just a one mode 100% output light?
I am just wondering what’s out there.
I am only familiar with on spot, on wide, on red, and then off.
Either just on and off or an on/off switch separate from cycling through the various modes.
The original Petzl Zipka headlamp had a basic on/off slider switch. It might be possible to find one relatively cheap now, but it’s like a decade old and way behind current tech.
For current stuff, any Zebralight headlamp will turn on high with one click, then turn off again with another click. They have other modes though, which offer much greater runtime by reducing output.
The Nitecore HC90 has a nice UI where you move a slider to smoothly adjust its brightness from off to max. It’s even pricier though, and would require a Li-Ion battery and charger.
I’m not very familiar with other brands of headlamps, aside from a few which don’t meet your criteria of being able to do simple on/off operation.
Yezl Y3. The on/off switch is in the tail. Mode switch is up front like a C or D Maglite. It has three modes…high…medium……low
It’s on sale and will run with a 26650 or 18650 with included adapter.
Haha, I can imagine trying to wear a Yezl Y3 on my head. 
SHhhhhhh…… don’t tell anyone willie doesn’t know how to read
Sounds like this may fit: Nitecore HC50 headlamp.
The HC50 works, but it’s worth noting that it can be difficult to shut the thing off without changing modes. Its switch can be half-pressed like a camera shutter, and that’s how it changes modes. But a full press is required to turn it off. So, it’s reasonably common that, when trying to turn it off, it will end up advancing to the next mode a split second before it shuts off.
Otherwise it’s a nice headlamp, and can be found relatively cheap (there’s a group buy happening right now). Just a little funky sometimes getting the desired operation due to the odd switch.
Just got the Nitecore 50 from the group buy. No switch problems at all. Very easy to full switch and half switch. This is a sweet headlamp.