Earlier quoted context omitted.
It seems entirely reasonable to me to quote larger prices per item, even much larger prices, for smaller quantities. Or even outright refuse to sell in small quantities. I mean, my grocer doesn't sell individual beans either. So why should wholesalers be forced?
They don't? I'm in London, and my local grocer will happily sell me one bean if I want. I've bought 1 bird chilli several times.
But what about prepackaged beans, like 500 gram pack? You can't open the package and expect to pay for part of it. Sometimes the beans are packaged by the grocery store with their branding. That's the same as not letting you buy an individual bean.