As some of you may recall, I like to try out various bits and occasionally have found some great values.
This is not one of those times.
I saw "10Pcs 3.175mm 1/8" Double Flute Spiral Cutter CNC Router Bits 17mm US Shipping" with free shipping for $9.65, i.e. $0.97 per bit.
The first bit broke while I was putting it in the collet.
The second bit lasted about 3 passes at the edge of a dish carving.
I'll try them in my Dremel, but for CNC use they are about the same as putting a pretzel in the collet.