How much should a person spend to get a decent power conditioner?

First you have to decide what your needs are. Do you want surge protection with some filtering to reduce some extraneous noise from your AC mains and components? This is passive conditioning.
Or do you want a power regenerator which takes the incoming AC from the grid and your service panel and cleans the signal (reducing noise) then regenerates a new sine wave to power your components, (Active power conditioning). These are needed in areas of an unreliable power grid or excess noise from old power lines and transformers, or areas of heavy interference.

The archives are full of threads with recommendarions.

I use two passive conditioners for my components since the power in my area is steady at 120V and there are new transformers installed in our neighborhood.
I have a Brickwall with surge protection which does a very good job of filtering noise from components and any stray interference such as RFI. It does not regenerate or regulate power from the grid.

I also have dedicated AC lines from the service panel to the receptacles at my audio setup.
I would recommend running dedicated lines with separate circuit breakers as the first step to reduce noise thru the AC mains.


Very good advice by David.

wisciman, daisy chaining 2 power conditioners is not an ideal way to lower the noise floor. You'll be running your components thru extra circuitry which will probably limit dynamics.

It would be preferable to use one conditioner for your analogue components and another one for digital devices.

a wall wart is a digital switching power supply,

They're used to power laptops and tablets, also small components like some DACs and streamers. Their design produces dirty power to the audio device and allows noise to flow back down the AC line and contaminate other components. 
To eliminate this noise, a linear power supply (which contains no switching circuitry) should be used.
Many of the audio manufacturers offer an LPS for their devices, plus there are many very affordable aftermarket units on Ebay.

A good conditioner will make your system sound more open and effortless, it will add weight and improve dynamics. In general however I haven’t found them to materially change soundstage, which is more a matter of low level noise better addressed via grounding solutions and the like. Rather against expectations I’ve never found conditioners to remove noise or so called grunge,

Exactly right. I'll add that due to the lower noise floor, there will be better separation between instruments. Also related is increased inner detail, you may hear effects and background studio sounds never revealed before.
 I like the more open and detailed imaging.