I think we'll allow you to keep your “English spoken” statement this time… but we're putting a black mark next to your name. 😉
I guess it's one of those things where it feels obvious in hindsight but there could easily have been a specialist term for it.
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I suppose like everything in collecting it's a “it depends” kind of answer.
Sometimes you get a bulk discount, sometimes you pay a premium. I suppose the more common the note, the easier it is to get consecutive so you might get a bulk discount.
Probably also depends on the amount of notes in the run. 3 probably commands a higher price per note than 2. But once you get to like 15, probably parity in note price as if it were 20.
For the notes I go for (British ~1800 to present, with a larger focus on decimal 1971-present), I've usually noticed a pair goes for maybe about 5-10% more than two singular notes in similar condition, so long as it's an out-of-circulation issue. A trio maybe 10-15%, and then it kind of remains there percentage wise for longer runs.
So not mega bucks more expensive, just a smidgen. As always, rarity & condition are the main factors.
But I admit thats purely subjective to what I look for.
One of those rules which, to my experience, is frustratingly true especially on the Scottish & Northern Ireland ones. Might just be a British notes though. But I'd definitely defer to Serial's opinion on a wider market. 🙂