I dislike making decisions. I really, really dislike making decisions. As a Libran, I tend to overanalyze and agonize over every choice, trying to weigh all the pros and cons. Reading books like Blink and taking courses on Decision Analysis have done little to get me through the slog.
Does everyone go through such an extensive cost/benefit analysis on their decisions? I hope not, because it can be paralyzing. It gets worse when you're poor. When you don't have much money, that money is "worth more" to you. $1 to a penniless person is worth more than $1 to a millionaire. The increased worth of money slides the scales on cost/benefit analyses, making life more complicated. You are driven to analyse all expenses with a more careful -- and frugal -- eye.
With most decisions in life, I focus on creating value over saving money. I will happily spend the extra money to buy premium quality meats, cheeses, and produce, because they taste worlds better and feel better in my body. It is, as they say, "worth it to me." That philosophy, however, is challenged when living significantly below the poverty line. For example, the difference between buying the Dance Only pass and the Full Event pass to bluesSHOUT is $100. In the past, I could focus on creating a certain quality of life (which would include the occasional purchase of a full event pass to a blues festival) and not worry about the specific numbers. Now, I must weigh the benefit of dance training against my ability to pay for rent, food, and rainy-day expenses. When you no longer have "extra money" to spend on hobbies, it is much more difficult to justify spending that money to enrich your life.
Being a Libran that is low on cash, more time is spent (wasted?) in the cost/benefit analysis process.
Meanwhile, a decade of psychology research indicates that our brain's executive function is limited and weakens with use -- just like a muscle. In case the term is unfamiliar to you: "executive functioning involves activating, orchestrating, monitoring, evaluating, and adapting different strategies to accomplish different tasks...It requires the ability to analyze situations, plan and take action, focus and maintain attention, and adjust actions as needed to get the job done." 
A decade of studies have shown that a brain exhausted from executive function use will perform "poorly" in subsequent and unrelated tasks. In one study, subjects were TWICE AS LIKELY to eat an indulgent chocolate cake over a healthful salad when tasked with memorizing a seven-digit number instead of a two-digit number.  The same goes for choosing leisure activites (watching TV) over "productive" activities (studying) after a mentally taxing task.  Willpower and executive function are finite resources. How you spend those resources (or, in my case, waste them) can have unexpected effects in your life.
(Seriously, read this article and listen to the Radiolab episode "Choice"; they're both totally worth it.)
Tradeoff resolution -- weighing options and then acting on it -- is particularly draining: "in one study, the scientists show that people who had to rate the attractiveness of different options were much less depleted than those who had to actually make choices between the very same options."  Evaluating options is very different when you don't have to act on that evaluation. You can be glib. Ever make a choice in on a plane ticket in advance, and then find yourself stalling and rethinking when it comes to click the "Purchase" button? That is tradeoff resolution at work.
Deciding what task to do next is also exhausting -- even before doing the work! Ever spend 15 minutes scrolling around in your inbox, agonizing over how many things you're supposed to be doing right now and not sure which one to do next? Work philosophies such as Getting Things Done and OmniFocus try to address this issue by removing the process of deciding what to do next; think of it like a context-sensitive, prioritized to-do list where you work from top to bottom.
The more you fill your life with menial decisions, the less mental strength you will have to spare for the choices that actually matter.
Tying it back into the previous thread about money: as your income increases, you free up your mind to focus on decisions and activities that actually matter (since a decreased value of money can often simplify choices dramatically). Those activities -- such as focusing on a single task (i.e. doing work) -- will then produce returns to give you more income. Success begets more success. On the flipside, it becomes clear how being impoverished (and a Libran) can create a snowballing effect in the mind and impact the ability to focus.
So the next time you're debating the purchase of that succulent $1.25 grapefruit at the produce stand, say "Fuck it" and buy the grapefruit. You have better things to consider.