RT1800 and RT3200 are pretty good candidates as far as pricing goes. (RT1800 is 39$ on Walmart 3rd party right now.)
Note that RT1800 actually has USB3, whereas RT3200 is USB2, but RT3200 has better OpenWrt support.
Both have been $50 and under at Walmart.
Another possible option for a super router is $79 Dynalink; if it was an Asus or Netgear with these same specs, they’d probably be selling it for $200.
Out of these 3 options, the RT3200 is the most well supported, so if you want it to work, probably get that one.
Also, WAX202 has been on sale for $29 or $39 often enough, but I think those may be gone; no USB, so, not the best unless you get it super cheap.
As far as Cudy goes that someone else recommended, I’d advise against it, because it’s missing USB and the specs are often the most barebone compared to alternatives on sale at the same price.
If I had a strict $40+tax budget, I’d probably investigate if RT1800 is supported properly, and get that one.
They’re missing USB, so when other options in the same price range can be had for the same under-40, like RT1800, then it’s kind of a bummer to be paying the same price for no USB.