Acoustic treatment question: do you agree with Dennis Foley that $46k to $65k is required?

@ shalommorgan, Very impressive, looks smart and purposeful. Did you measure the room performance as you were adding treatment?

@ pureaudio, wow, I am appalled at the good money you spent and without the reward. I sympathise.

Re: Denis Fooley, what can I say?

@ hilde45, I did offer a gentle warning about the above gentleman. It is really not necessary to pay that much to transform your room's performance. DIY goes a long way in keeping costs down. My 2 bass traps cost me about $220  Just these 2 made a huge difference but measurement shows that I need at least 1 more.

@bpoletti. your dust collecting ficus trees unfortunately can not in any way address low frequency problems.

Fact: Lambda = velocity divided by frequency, so a 40Hz wave is 343/40 = 8.58m, over 28ft. long. At 20Hz it is double that length!

In the photo below is the start of a bass trap, built from cheap construction timber, plywood and rockwool, the closest equivalent to OC703 I could find.

https://imgur.com/Lwx8NTR          

Did a little search on "fake plants." Some really funny replies and results, but not much in the way of confirmation they can help much. https://forum.audiogon.com/discussions/fake-plants-behind-speakers-a-good-idea

That price for activated carbon above is totally out to lunch. Activated carbon starts at about $0.5/kg.  Let's they need a specialty grade so 10x maybe. They aren't buying it on Amazon.  Only highly refined scientific grades would be the cost quoted above.

Well, I am truly in need of more education. My room treatment cost less then 0.5K

Lemonhaze. I measured the room response with a small omnimic and cell phone. I was fortunate enough to build, change, add, subtract, listening and listening again as I worked through the build process. This gave me the ability to hear what worked and what didn’t. My ears guided me. (I’m now diving deep into room measurement tools/ software.) and yes it measures great down to 30hz. 
A small room needs about 800-900lbs of activated carbon to provide meaningful results. I paid $165 per 50lb bag of coconut shell activated carbon. Just as a reference.  
I agree that not everyone will spend the amount of time building out their own room, as I did. From a few acoustic panels to a world class music room, the important thing is we enjoy our time relaxing and listening to great music. Every room is different and will likely require a unique solution.