I wonder if the sentence make sense:
The moments like that you wouldn’t meet by the dozens (in your life), it’s by-the-piece/one-off stuff.
Thank you.

“by-the-piece” doesn’t really make sense to me there, but otherwise it makes sense. However, I would delete the initial “The”, and “by the dozens” should be “by the dozen”. I would also change the comma to a dash.

Thanks for the correction, Dozy.

“By the dozen” was my deliberate choice though, relying on the definitions by
sold by the dozen ( used for saying what units of measurement are used); In the amount of: letters by the thousands

Since hardly could you expect moments packed/weighed by the dozen, rather occurring by/in the amount of (the) dozens, my pick seems reasonable, doesn’t it?

Eugene, I’m sorry, I do not adequately understand your last post.

However, looking further into this, it may be that there is an AmE/BrE difference. The graph here of BrE usage shows “by the dozen” dominating (matching my natural inclination), yet the graph here of AmE usage shows “by the dozens” approaching almost equal frequency in recent years.

My fault, Dozy–wasn’t accurate enough in citting sources.
7. a. In the amount of: letters by the thousands.

14used in calculations and measurements
a.used for saying what units of measurement are used Floor coverings are priced by the square metre. Industrial workers are generally paid by the hour.
sold by the dozen … british/by

Relying on these, made me conclude “by the dozens” would be more to the point referring to moments. Should you stick to one universal pattern (“by the dozen”) nowadays?

I don’t think it makes any difference what is being referred to – whether moments, eggs, people, whatever. It’s a set pattern that’s the same for everything. However, I know the pattern as “by the dozen”, while others, especially it seems in the US, know it as “by the dozens”.

The price is cheaper by the dozen (as opposed to buying by the unit.)

The salesman, in dealing with the buyer for the retail chain asks, “How many dozens do tou want in each color?”

The word “grocer” originally was “grosser” for the store would buy by the gross to get a good price (especially saving on shipping) and would sell by the each to consumers who didn’t need many.

UK - as discussed, ‘How many dozen do you want of each colour?’

Will you excuse me being so stupid, but I’m absolutely in two minds now as to validity of “letters by the thousands”. Should you sue thefreedictionary and put it “We receive letters by the thousand” (“He’s received threats on the phone by the dozen lately”) (“In another league, he would score by the dozen each season”) (“No antibiotics would mean people dying by the hundred/thousand from a mere flu”)?
Or is it a case of BrE vs AmE really?

All I can tell you is that ‘letters by the thousand’ is valid in the UK, whereas ‘letters by the thousands’ appears to be common in the US.

We get letters by the thousands in left-pondia, but visitors by the score, proving once more that the only thing consistent is our inconsistency.

(A score is 20.).