For a show n tell at Hackerspace, I put together an overview of expenses / purchases one should consider as one's income grows.

This stems from a simple personal observation about a Leatherman. After university, my dad gave me a Leatherman as a Christmas stocking-stuffer; I then promptly put it into a drawer and forgot about it. Fast forward a year or two, and one day at work I was going to have to do some cable management in our data center, so I brought my Leatherman.

I expected to only use it in the data center, however I also used it to fix a window lock, and later to open some bottles of beer. So I brought to work the next day, and found that I kept pulling it out of my pocket to hack on something, so I started carrying it everyday.

A Leatherman is very cheap compared to how much it changes your life for the better. Chances are, there are other such "epic wins" at each income level.

Preventing us from being consummate hackers are two related problems: 1) it's not obvious how much something will change your life for the better until you try it, and 2) we are constantly growing into higher income levels, and can afford new quality of life hacks. So we need a map of what other people have found useful at what income level.

Gleaning what various financial advisors and people have mentioned online, I've the following start:

USD/month  Epic Win

10^2       Leatherman
           Earplugs 
10^3       Smartphone w/ 'Net access
           Kindle + libgen
10^3.5     Headhunter / long-term career shepherd
           Quality bed w/ blackout curtains
           Quality desk job chair
           NAS boxes as data diaries (never delete, just archive)
10^4       Maid
           Therapy 
           Personal Assistant
           Tailor your physical environment more -- ???
10^4.5     Country / Gentleman's Club as relaxed office     
           A really, really good assistant
           Eudaemonia Machine
10^5       Car w/ Driver, Prop w/ Pilot
10^6       Jet w/ Crew

What items/services would you add per income level which were easily worth the expense? Has anything had an unexpectedly high value?

It seems very difficult to determine what works, so we should budget a fixed percentage (say 5%) of our disposable income for experiments, i.e. we should always be trying to improve our quality of life.

Update 2016-11-14:
Across all income levels, surrounding yourself with people you can trust is also recommended.