I like that we now have a prostitute picture on file. (REUTERS)

Sure, get a Groupon for a massage with an unhappy or ambiguous ending! Hire the cheap roof repairman! Send your kids to robot daycare. Switch to Geico! Cut corners everywhere you like. Buy a mere $14 worth of artisanal cheese rather than the full $19 pack when you head west for the GSA convention.

But when it comes to members of the Oldest Profession, don’t try to haggle. Especially not if you are a member of the Secret Service visiting Colombia.

Everything I know about prostitution, I learned from “Pretty Woman” and the James O’Keefe ACORN sting. I know it is the World's Oldest Profession, with the possible exception of hunter-gathering.

So I read the New York Times interview of one of the Colombian Secret Service prostitutes with rapt attention.

First off, she is not a prostitute, she is an escort. This is a subtle but meaningful distinction.

“It’s the same, but it’s different,” the escort told the Times. “It’s like when you buy a fine rum or a BlackBerry or an iPhone. They have a different price.”

Does my BlackBerry offer services that I am not aware of? Clearly, I’m asking Siri the wrong things.

Many people have been lumping this story together with the Party in the GSA as an example of the same kinds of wasteful, disgraceful behavior by government employees. But I think this is misguided.

The money shot comes in the second paragraph.

“The disagreement over her price — he offered $30 for services she thought they had agreed were worth more than 25 times that — set off a tense early morning quarrel in the hallway of the luxury hotel involving the woman, another prostitute, Colombian police officers arguing on the women’s behalf and American federal agents who tried but failed to keep the matter from escalating,” the Times reported.

We should have sent these guys to the GSA convention. Clearly, they drive a hard bargain.

See, this is the difference between spending other people’s money and spending your own.

The GSA could afford $75,000 to construct a bicycle as a team-building exercise. Why not? They weren’t paying for it.

Nineteen dollars’ worth of artisanal cheeses? Don’t mind if I do!

But the Secret Service wouldn’t even shell out $800 for a full-service evening with an escort. That’s about as penny-pinching as they come. They spent money on two bottles of Absolut for the table earlier, but evidently only under duress.

If they hadn’t been trying to save money, we might never have known. This is a fact that they should publicize. What is more American than trying to save money on occasions when you really should just pay full freight?

That’s almost impressively cheap. You can’t expect a full evening of service for less than the cost of an iPhone. If you could, no one would buy iPhones we’d still buy iPhones.

But instead of praising the only government employees who have publicly displayed wild, insane levels of frugality, we’re condemning them.

I am not commending the Secret Servicemen, obviously. But I do admire their parsimony.

Why fire them? Everyone has been complaining about government waste. Yet here are several men who have received evenings of quality service and managed to drive the cost down from $800 to $225, in a mixture of dollars and pesos. Get these guys on the budget committee. Send them to the GSA. There’s no danger of their wasting this kind of dough on commemorative coins.