I'm working on a piece of structured data, in JSON-LD format (should it matter).
While looking through the price property page of Schema.org, I saw that you can also add text as price value. However, it doesn't seem to be documented anywhere what texts are allowed.
Does anyone know what texts are allowed?
I've tried to fill in random texts while using the Structured Data Testing Tool, but that gave an error that it didn't get recognised.
Schema.org doesn’t restrict (nor document/recommend) what kind of Text value the price property can have.
Most prices will have a Number value, and unless you have a good reason not to use it, you should go with Number, too, following their "Usage guidelines".
I guess possible reasons for expecting Text could be:
CMS that don’t (easily) allow to output the price separately from the currency symbol. Having "5 EUR" as price is better than not providing a price at all.
Authors that want to say "gratis" or "free" instead of "0".