Hey Monte,
I can say that the Tesoro Bandido II µMax has the most views because it is a well known Tesoro Classic - Still, at $450 shipped with the 6" coil, it is very close to the cost of a NEW Vanquish 540 Pro Pack or a Garrett Apex (of which you have 3). Pristine versions are hard to find and I'm sure there are a few souls out there with a need to do some Beep & Dig. Will they step up to your asking price ? Time will tell.
As for the rest of the test units awaiting a good home, just a matter of finding someone needing a detector of that appropriate skill level.
I can appreciate the outlay of $$$ you made on this budget detector (<$500) comparison project - a sizable billfold of Franklins, more than I can spare for comparison testing. Hopefully, there are some folks out there that could use a spare / loaner for a friend / kids / grandkids, so you don't have to eat the total costs of your project. That would be painful . . . .
r
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Just One More Good Target Before I Go . . . .
800 / Deus