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

I don’t understand why you keep posting that.

Because it was the original balanced power supply direct coupled (matched) complimentry jfet buffer that Nelson designed for the Lightspeed.
Afterwards it became (I believe the cruder) unbalanced supply re-configured capacitor coupled p channel jfet buffer (didn’t need to be matched) for the B1
Once again go away your stalking, also calling my product "thing"? you really need to see someone.

Cheers George

If you play digital, the MSB DAC can drive any amp, using passive analog volume control only. 

$1.000.000.000.00

@honashagen  you ask  question , the answer is very simple
Absolutely no difference how much money you can spend , the  pre
amplifier -is device  can change the sound in only one side- make sound
worse, The  ideal preamp just  no change the sound quality