Who would have predicted that the % key on our keyboard would get such a workout this year? Just when we’d stopped obsessing about the 99% vs. the 1%, we started pitting the 47% against the 53%.

Soon, kids will be asking, “What did you do in the class war, Daddy?”

Of course, as F. Scott Fitzgerald said, the rich are different. How are they different? Well for starters, they pay more to get their dishwashers fixed.

Last week, I wrote about the “Potomac rate,” the rate some service providers charge you if you live in a nice part of town. I mean no disrespect when I say the Potomac rate is likely to be higher than, say, the Langley Park rate.

I wondered whether this mythical pricing structure really existed. Some readers were eager to tell me that it does.

Greg Billings lives in, um, Potomac. About four years ago, his dishwasher was acting up, and he called a repair service. “The dispatcher quoted me $49.95 for the service call,” Greg wrote.

After a routine visit, the repairman began filling out the service ticket. The price: $59.95.

Greg protested, saying the dispatcher had told him the cost would be 10 bucks less.

The repairman said: “This Zip code? Did he know where you lived?”

Greg responded: “I assume he did. You arrived here with the address in hand, didn’t you?”

Greg said his father is a good source of information on what major repair jobs will cost. Wrote Greg: “He tells me what it should be, but then adds on 10 to 15 percent for what we joke is ‘the Potomac Zip Code Surcharge.’ He’s usually spot on.”

Margaret Keegan lives in Rockville. She received what she thought was a high estimate from a tree service. She asked what was up.

“I was told by the owner that I was given the Potomac rate, not the Rockville rate,” she wrote. “The estimate was adjusted. I have not used that company again.”

Every jurisdiction has a Potomac, whether it’s called that or not. For Dede Haskins and her neighbors, the inflated price is called “the Great Falls Bump.”

Dede lives in western Great Falls, less than a mile from the Loudoun County line, in what she says is a nice, but by no means high-end, Great Falls neighborhood. “I’ve actually heard my neighborhood referred to as ‘the slums of Great Falls,’ ” she wrote.

A couple of years ago, Dede got a quote over the phone for gutter cleaning. She accurately gave her address and said her home was near the Loudoun County line.

“When the company arrived to clean my gutters, the service person was visibly agitated and kept complaining about my location not being Sterling, while attempting to increase the price,” Dede wrote. “I held firm, and they went ahead and honored the quote, but clearly weren’t happy about it.”

Of the Great Falls Bump, she wrote: “I think it’s ridiculous, but believe it is totally real.”

Ken Wild lives in Arlington County. About 20 years ago, he needed the regulator on his “paleolithic” oven looked at. (The oven was about 50 years old then but had never given him much trouble.)

Wrote Ken: “I apparently betrayed a brief shudder when he told me the cost for his 20-minute job, and he said something like, ‘Well, you’re already getting the South Rate.’ ”

Ken asked what the South Rate was. The repairman told him that it was the rate for South Arlington. The same job on the other side of Arlington Boulevard would be 10 to 15 percent higher, he explained.

The light bulb went on over Ken’s head: “I realized that the large majority of high-income housing in Arlington was in the north.”

That’s when Ken started referring to where he lives as “the South of Arlington.”

Why? Well, have you ever noticed how people never refer to their vacation as having been in “southern France”? It’s always “the South of France.”

It’s Ken’s way of classing up his neighborhood.

Tomorrow: The other side of the story — service providers explain their pricing.

To read previous columns, go to washingtonpost.com/johnkelly