Least Expensive Power Conditioner/Surge Protector That Won't Worsen Sound

I've had good luck with Audioquest Niagara.  Tried many over the years (a few mentioned above . . . ) and my latest move further into a rural area has me contending with power issues 'big time'.  This unit has successfully handled them 'and' its one of very few units that doesn't affect the sound.  Had some pretty pricey products mentioned above not cut it in that sound department.

Ah yes, as erik mentions above . . . I still rigidly decouple the entire deal from energized during lightning storms.  But my power issues were interstingly enough not to do with electrical storms so much as reductions in power followed by surges.  That Audioquest seems to handle them in that no damage.  That didn't happen when I first moved into this place with no protection and I had a $$ Plinius repair bill to deal with.

+1 on Chang Lightspeed

Brick wall out of PA for $300, matched several-line conditioners in the $1500 

range andSterphile used to have it in class-B  which is respectable ,I bought 2 and find them pretty effective ,I upgraded mine by upgrading  several internal capacitors 

and installed a Furutech power cord to make it better still , most everything can be bettered if you look inside it ,whst most Audiophiles don’t realize is Thst on average 25% of the-cost goes into the build ,the rest R&D  overhead,and dealer mark up.

If they are doing it right, parts are marked up 5 times in manufacturing. The other costs you mentioned should be marked up 3 times, including labor. Then, that price is doubled twice before the point of purchase. The margins in audio are what makes it all go round.