My recent post on a woeful tip I not-so-advertently bestowed on a hard-working Grand Central beer man elicited a comment from a reader calling me a cheap-ass for not tipping a buck.

Granted, I’m considering the source — said commenter is an angry Rhode Islander who’s happiest when he’s stirring things up. But he raises a valid question: What’s a fair tip for a Grand Central beer man (and when I say “beer man,” I’m including that one woman who operates a Grand Central beer cart too).

Of course, the pay scale of Grand Central commuters ranges from the Greenwich hedge fun billionaire to schoolteachers and reporters who can barely make their mortgage. But what’s a fair middle ground?

I tend to tip a quarter or two. Here’s how I see it: If I’m buying a $2 beer at a deli outside Grand Central, I’m not tipping a penny. If I’m buying a beer from one of those bakeries or pizza stands inside Grand Central, I’m not tipping a penny.

If I’m buying a $7 pint at Annie Moore’s, I’m tipping a buck.

So if I’m buying a $2.25 Sam Adams in Grand Central, the tip should be somewhere in the middle, like 25 - 50 cents. The guy is doing the same thing as the worker at the bakery or pizza stand across the Grand Central concourse, but since it’s a lone owner-operator, I’m inclined to throw him a little something.

I have no idea how well off the beer guys are, but judging by some of their haircuts, they’re not wallpapering their bathrooms with Benjamins. If any beer guys (or gal) read this, I’d love to hear from you about fair tips.

How much do you, fellow rider, tip?