Is it common in German to use "twelve-hundred" (Zwölfhundert) to convey the integer 1,200 (say "that'll be $1200 please"), or is it more usual to say "one-thousand-two-hundred" (eintausendzweihundert) instead?
For years in the range 1100 to 1999 the "zwölfhundert" variant is common in Germany:
The house was built in the year 1980.
Das Haus wurde im Jahr neunzehnhundertachtzig gebaut.
The variant "tausendzweihundert" is very, very uncommon for years in that range.
The variant "zwölfhundert" sometimes is used for other things but it is uncommon when not speaking about the date of a year. The "tausendzweihundert" variant is used in these cases:
1980 years have been passed since then.
Seither sind tausendneunhundertundachtzig Jahre vergangen.
1980 people live in the house.
Im Haus leben tausendneunhundertundachtzig Leute.
eins Tausend zwei hundert
There are two possible ways to write this word:
- eintausendzweihundert (without the "s" between "ein" and "tausend")
- tausendzweihundert (the "ein" is implicit)
Sometimes you hear the "zwölfhundert" variant when not speaking about a date of a year. Indeed I have already heared people saying this when talking about a price.
However it is quite uncommon and I never heared persons using this variant when the number is not a multiple of 100 (when not speaking about dates).
Therefore I think people using this variant use it when they want to give a rough estimation (by rounding the number to the next 100).
In my experience it's not so common anymore. In your example, $1200, one would rather say eintausendzweihundert or tausendzweihundert. When someone says "zwölfhundert", it is usually in informal speech, and more in the sense of a rounded or estimated number rather than an exact number.
The use of it probably originated in special contexts where things were/are weighed or counted in units of hundreds and numbers usually stay under 2000.
Only when giving an exact year A.C. zwölfhundert-, dreizehnhundert-, etc. is common.
Yes, it is common. And yes, one way of saying it is probably just about as common as the other.
Caveat, however: In some languages (like English, for example) it is common to name the hundreds beyond 19 - Like "twentyone-hundred". This is not used in German, normally. "neunzehnhundert" is about the highest number we would express in "Hundert", everything beyond that would be expressed in "Tausend".