TO "make much of" something is to see it as being important, significant, relevant, reliable, or some such. For example, if you said, "Jack made much of the job applicant's two college degrees", that would mean that he thought that the college degrees were very important and relevant.
To "make too much of" something is to give it more importance than it deserves. (Of course this could be a matter of opinion.)
So the quoted sentence is saying that people sometimes give more importance or significance to statistics than they should.
"Next to" means "almost" in this case.
Imagine a scale of possible prices, from zero to infinity. What sits immediately next to nothing (zero) on that scale? "Almost nothing."
"How next to?" is a jocose question whose purpose is to determine the degree of "almostness": how close to zero, exactly, is the price? Does "almost nothing" mean a dime, a quarter, or ten dollars?
Closely related is the idiomatic phrase "next door to":
STELLA:
A rhinestone tiara she wore to a costume ball.
STANLEY:
What's rhinestone?
STELLA:
Next door to glass.
In this excerpt from A Streetcar Named Desire, a play by Tennessee Williams, Stella explains to Stanley (who thought that he was looking at something valuable) that the tiara is really, really cheap. "Next door to glass" means "Those are not real diamonds. They're fake. They're made of rhinestone. How expensive is rhinestone? Barely more expensive than glass."
Best Answer
The definition of "gringo" according to Merriam-Webster Dictionary:
Here is the definition from Oxford dictionary:
So if you are visiting these countries (Latin America, Spain, ...) you may face "gringo pricing" which is the overcharged price that foreigners may be presented with when shopping for something in these countries.
This may happen because people in these countries may think that since you are an American or you come from Europe, Canada, Japan or ... you are very wealthy (or you are not aware of the exact price), so they may have a special price for you.