How much do I need to spend to get a preamp that sounds better than no preamp?

In the same sentence you also said,   

no more bench testing for measurements and specs to keep the manufacturers and reviewers honest, it'll make you think twice on what to believe now, without the proof to back it up.

Your last post is classic cherry picking...and you are an expert at that. The quote above is a not a maybe statement, it is your presumption of fact. All you really had to do was wait for the answer from the source, JA is pretty good at following up questions. Hey, as long as you get the word out first, it doesn't matter if it's true or not. Kind of like the media these days. When the truth comes out, the best you can do is offer a weak, half hearted statement at a later date. I wasn't offended by your so called apology, I was bothered by your dishonesty at creating the post and your continued attempts to justify it. Your character, or should I say lack thereof, continues to shine through. 

Since the topic is really about " gain ", let me say this. I have a large assortment of amplifiers, included a few pro amps, which all have input gain controls. Using these amplifiers, I have a choice, of keeping the controls on the amps at max, and using the preamp ( s ) volume controls at a lower setting, at about 9 - 10 o’clock. However I find I prefer the sound of the system with the amps controls turned down, to the point where the preamp ( s ) volume control is at about 12 - 1 o’clock. I have tried going from source to amps, and while it is clean ( possibly a little cleaner ) without the preamp, with the preamp ( s ), the drive, dynamics, well, pretty much everything, is better to me through the preamp ( s ). Enjoy ! MrD.

Your last post is classic cherry picking...

No you are cherry picking and must more likely have your back up over the "snake oil" voodoo'ist statement I made. As I'm a great believer in measurements, as that's how all gear is designed and made, and then listened to.
And those measurements can help buyers/users choose right amps for speakers and/or right speakers for amps, instead of the many "well serving" here but wrongly saying "buy this" it sound great, but don't have any idea if it will to the job measureless wise.

Cheers George 

@almarg superlative perspective, and as always, sage advice.
Thank you, Al

I do not believe "gain" to be the main issue here.  IME, the reason some hear improvements in dynamics and bass when moving from a passive to an active preamp is due to improved impedance matching through the volume control and consistent current delivery.  An active buffer (with or without added gain) can make the source's job of driving an amplifier easier by allowing the source to see a high input impedance into the volume control and the amp to be fed a consistently low output impedance following the volume control.  With the high'ish output of today's sources (i.e., CD players at 2V and  DACs at 2V to 6V) gain is probably not the main reason people hear improvements due to active circuitry.