Broughton Terraformer, they pop up used in the classifieds here all the time for $110-$125
Others to consider:
Broughton Azure Drive
Fairfield Circuitry Barbershop
EHX Hot Wax
TC Electronics Spark (full size)
TC Electronics MojoMojo
Digitech Hardwire CM-2
I love the Spark. I loved it on guitar (even going so far as using it in an FX loop for a clean boost) and I love it on bass. Only 2 knob EQ and no blend, but there is SO MUCH range in those 2 knobs, I can get anywhere I want to be. Gain - no grit at 1/4, a little at 1/2 up, and a fair amount of soft tubey (unless you crank the treble) overdrive if you get it 60%+ up. Has a 3 position toggle for emphasis, clean-low-mid, I keep it low. Bass knob up around 2 o'clock, treble noonish - but it's still a usable sound with treble higher or lower. Plays well with other pedals.
The CM-2 I like EXCEPT the stupid click knobs, I always need to be right in between 2 clicks for volume.
There are a million bass overdrive pedals out there, but from what I’ve seen, for a nice tubey overdrive, the Darkglass Vintage Microtubes does a really good job, and it can do a subtle overdrive. My other pick would be a Way Huge Pork and Pickle.
I cannot get rid of high end artificial sounding ugly artifacts with either the VM, or the AO, which I own and like. I end up low passing around 4K to get rid of them. The AO does really good low gain. It could be because I use active basses and a rock sound with a healthy but not overwhelming high end, the DG stuff just takes the highs to an unattractive place.
That or TC spark booster...full size pedal,not mini..
Spark. Spark. Spark. Readily available and not expensive. Not the mini, you want the big one.