By Justin Melvin

As suggested by “shift” in the flavortext, each statement has been Caesar shifted. First, solvers find the amount by which each phrase has been shifted, and use those amounts as an index into the alphabet, resulting in the following phrases, shifts, and letters:

Phrase Shift Letter
The head thief is similar to a corpulent pig who never produces adequate basswoods, deceased like. 23 W
The impoverished safe place, (the one for small mendicants), gives too much wealth to the wealthy. 8 H
Several family home frighten, exhausted in the acquisition. Trigonometric function ladies for. 1 A
The one who multiplies the number of languages by two goes on an alternative search engine to. 20 T
Amazing popularity in lupine cannibalism. 16 P
Continuously moistening your piehole, attempt to eat. 15 O
Be like groin region or ghost world goofy, black-and-white hard-boiled detective clever, but. 15 O
An educated person whose head could be opened with a key is a greater idiot than an uneducated. 18 R
A habitual drunkard’s four inches quiet: having to do with this area idiot’s good qualities. 18 R
A trio makes a casual acknowledgement a mystery, if a pair of them are pushing up daisies. 9 I
Repudiate your personhood, for Santa’s helper’s rice wines. 3 C
The guy who lives on wishful thinking changes his eating habits, coping. 8 H
Appeal to divine sources, a fried torus set fire to my tube to cook your hens’ products. 19 S
When logic stretches to get something, if you don’t listen, she will put your Boscs in a crate. 1 A
A kind of beer, a trophy’s better than a decision made by decree. 25 Y
Idiots require a sin more, but only wise guys risk the better for it. 19 S

Reading the amounts shifted as letters yields the clue phrase WHAT POOR RICH SAYS. Combined with the title (Unfortunate, suggesting Poor; and Al, an abbreviation for Almanack), the flavor text (hundreds of dollars, suggesting Benjamin Franklin, who appears on the $100 bill), this suggests Poor Richard’s Almanack, by Benjamin Franklin.

Each phrase almost describes a quote from Poor Richard’s Almanack, but there’s been a “second shift” performed on the original quote—namely, that one letter has been moved in the aphorism, potentially changing spacing and punctuation. The numbers from the puzzle provide a guide for how many letters are in each word of the modified aphorism.

Here are the modified, and original, aphorisms, along with the letter that was “shifted” (in the order they appear):

Modified Original Letter
Arch rogue, is like a fat hog, who never does good tilias dead as a log. A rich rogue, is like a fat hog, who never does good til as dead as a log. I
The poor haven little, beggars one, the rich too much, enough not one. The poor have little, beggars none, the rich too much, enough not one. N
Many estate scare spent in the getting, sine women for tea forsook spinning & knitting. Many estates are spent in the getting, since women for tea forsook spinning & knitting. C
Tongue doubler Bings trouble. Tongue double, brings trouble. R
Great fame in when wolves eat wolves. Great famine when wolves eat wolves. E
Keep your mouth wet, feed try. Keep your mouth wet, feet dry. D
Be nether silly, noir cunning, but wise. Be neither silly, nor cunning, but wise. I
A learned lockhead is a greater blockhead than an ignorant bone. A learned blockhead is a greater blockhead than an ignorant one. B
Sot hand Silence: areal Fool’s Virtues. Sloth and Silence are a Fool’s Virtues. L
Three make “yep” a Secret, if two of them are dead. Three may keep a Secret, if two of them are dead. Y
Deny Self for elf’s sakes. Deny Self for Self’s sake. S
He that lives upon Hope, diets faring. He that lives upon Hope, dies farting. T
Pray donut burn my Hose to roast your Eggs. Pray don’t burn my House to roast your Eggs. U
When reason reaches, if you won’t hear her she’ll box your pears. When Reason preaches, if you won’t hear her she’ll box your Ears. P
Ale, an Award, ’s better than a fiat Judgment. A lean Award is better than a fat Judgment. I
Fools need A vice most, but wise Men only dare the better for it. Fools need Advice most, but wise Men only are the better for it. D

Reading the shifted letters in order yields the answer, INCREDIBLY STUPID.