Can you guess the meaning of grincheux?

My local butcher (boucher) can be a grumpy so-and-so. His interaction with customers is utterly unpredictable, veering from monosyllabism to sarcasm or rudeness, or on a good day, seemingly forced, ironic cheerfulness. 

At first I thought it was just me, but speaking to friends in the village, plenty of others agree with my assessment of this irascible meat monger. Some even wait until the boucherie’s afternoon opening hours to buy their saucisses, when the man’s much more affable son has taken over customer-facing duties – presumably with the early-rising viande grinch having a post-lunch snooze (sieste).

He is also well known for his prices, definitely the wrong side of reasonable.

I almost caused an international incident recently when I did the unthinkable – I went in to the butcher’s, but not to buy meat. It was nearly lunchtime, and I needed a solitary tomato for a sandwich. I happily proffered the tomate for weighing, along with a 50-centime coin. He was stunned. ‘Que ça?’ (Just that?), he uttered in disbelief at my small-fry purchase. It was hardly my fault that he decided to sell fruit and veg once the village épicerie closed a year ago. 

He did not know whether to charge me for the tomato and appear mean, or grudgingly give me the tomato for free. Both options probably riled him equally. 

As for ‘grinch’, our word is akin to the French word for grumpy: grincheux, with origins in the 17th Century – ‘qui grince des dents’ refers to someone who grinds their teeth. His were certainly gritted as he muttered ‘au revoir’. 

Me? I had 50 centimes and a spring in my step (marcher d’un pas léger).