Yes - there are a few sub $100 DNAC devices
It may be easier to decide how many (and what size) batteries you want the mod to hold.
There's some 11/11 deals on at the moment and Black Friday next week so there should be more discounts and thus more devices under $100 to choose from but off the top of my head there's ...
VT75D which takes 2 18650s
VT75C which takes a single 26650 or 18650
Mirage which takes a single 18650, 20700 or 21700
I went for the VT75D as I wanted a dual 18650 mod as I already had a few other dual 18650 mods that I have bought batteries for in pairs and have always been charged together in the past that I don't want to get mixed up in single or 3 battery mods.
The Eleaf Invoke is my budget mod choice (I think I abused a code to get it down to £24 inc del from Fasttech) which runs great with the stock firmware, Arctic fox or Sur_myevic altho the battery doors can be a bit annoying.
The RX 2/3 (my 2nd choice) can be had for under £40 if you can find stock (ebay amazon) and maybe £30 if you're not picky about the colour, it's a little bigger, heavier and more robust than the Invoke and can run FunkyJunky's tubomyevic firmware, which might be enough to make it your first choice