??? Established Manufacturer or Take A Chance ???

Due Diligence is no harm done, it is the equivalent of giving priority to Caveat Emptor when making a purchase.

My situation is such, I don't care about resale value, anybody who knows their stuff will immediately see where the spends have been done in my audio equipment.

Purpose produced Schematics, not copies of others designs are the fundamental.

Topology is the creation of the Builder Designer, no dimensions controlling the selections of the components, if the casing has to be 18"W x 18"D x 8"H and be produced from a certain gauge of Metal Sheet, with 'X' amount of Ventilation catered for, then that is it, or choose a different design for an Amp or other device if the mass does not work out.

Hand Wound Bespoke Produced Tranx's both Power Supply and Output are not normal and when done as mine are and at my present age, have gone from a One Person Handling to a Two Person Handling if injury due to weight is wanted to be avoided.

Point to Point Circuitry and voicing of the End Sound with End Owner having an influence on which components are the critical ones to be maintained in the final assembly is where the service really comes to the fore.

If the End User wants to tweak the BOM by trying out a range of components and pay the Designer Builder to assist with this investigation, there is a lot on offer, to the point an exchange of the device may never be sought anymore, well that my experience.

My First EE/Designer/Builder was met in the 90's and they have produced Three Builds for me, and are working on the latest at this current time.

My Valve Input/ Output Phon' is built by an EE/Builder/Designer who was producing Phon's as a side hobby, and I was encouraging them to take them to Bake Off's and Exhibitions attended by the public. These Phon' designs were well received and at a later date adopted by a well known UK Company selling into the Analogue Market, where models were to be marketed at £10K+.  

My DAC was produced through an intermediary and was built in Hungary by the EE/Designer/Builder on my behalf. It is now quite a few years old, does it matter if the Original Builder is still accessible, for me No, any warranty is long expired.

If one wants a guaranteed chance for a sale of a item at a pretty much easy to learn market value, then Branded Products are the way to go, even buying used items from well exposed Brands, is a way to reduce the cost of entry into a certain level of audio.

My methodology of purchasing audio equipment is one that is most likely more cost friendly than buying used items, and has the option of creating a personal preference for voicing, (very very attractive option) on a build that is already of to a very good start as selected schematic-Topology-BOM for audio equipment.        

Let me modify the question slightly.

At what price difference would you purchase a no-name item over an established Brand name?  This is a sliding scale and could have notional breaks at say 20%, 40%, 60% and 80% discount.

Change the premise a bit, and introduce sound technical innovations with a no-name manufacturer, versus an established technology and brand.  I personally am tempted when the price difference approaches 50%.

A complication is that the innovative little guy probably cannot afford to protect his intellectual property with patents and sooner or later a Brand will adopt his technological breakthrough.

Somebody had to buy the first SME tonearm.  Somebody had to buy the first class-D amplifier.

Seems like the only reason for preference in long term established company is for future resale and/or maintenance.  Both importance is subjective - what’s acceptable to some may not be for others.

@kennyc exactly; and based on OP’s statement, it would seem that resale value isn’t the driving concern here

You are getting pretty long in the tooth & have an itch to build what will most likely be the system playing at your wake

@freediver get amps that make your speakers happy, that make them sing. Audition amps with your speakers, of course. How the end sound, ideally, captures your heart is all that matters. Not the price, nor how many years the manufacturer has been in business, etc.

Besides, established companies are less likely to disappear outright, but they do get bought out and the new owner may decide to end support for legacy products. Try to get vintage Levinson serviced by Levinson.

What are your speakers? 

As a manufacturer that is not well know I would say to contact the one you are considering and as about issues or future repairs.

As a manufacturer we are all point-to-point wired using the best parts versus even the well established manufacturers.  As a repair facility many repairs are because of lower quality parts and circuit boards over a period of time.

Designs can be simple even if a manufacturer is out of business if you know a excellent repair facility with a technician that has a degree in electronic design or has been doing repairs a very long time.

Happy Listening.