Amps which are Great, but either Unknown or Underpriced

The ARAGON 8008 (INDY AUDIO LABS). Not really underpriced, Very unknown, But I love the hell outta mine!!! From its physical styling to its first rate parts count to its high level of performance to its fit & finish the unit just screams GREATNESS. And all for Not??? Its a damn shame that INDY does nothing to promote this thing or any of their products for that matter. The only review to my knowledge, was from The Absolute Sound, and they seemed liked it too??? As for advertising,"NOTTA", I surely hope they don't go "THE WAY OF THE WIND" because of "LACK OF"???

Does anyone consider Blue Circle amps as an unknown?

Blue Circle has been around for a while, probably not as well recognized but certainly good gear.  Their new integrated amp with selectable tube/solid state input section looks pretty cool.

Quicksilver Audio running GE 8417's.

Nelson Pass Forte Audio.

Yes the OP asked for less expensive even vague yet people continue to drop some of the biggest names out there.