While I would "put a value on" something, I don't think I'd ever say either "What value is it?" or "What value is on it?". In English, I'd say "what is it's value?" at a stretch - "what is it worth?" would be the most natural translation, I think.
I would understand "What value is on it?" if I came across it, but I think it might be a reverse-Béarlachas. It's a construction from *an ghaeilge" that sounds OK in Hiberno-Irish.
I often hear 'of what value is it', especially in English lit. But it implies that it is of no value.
BTW: 'How much is it worth', which is essentially the same as 'what is it worth' and at least as common was just rejected. I didn't report it because this statement (what value is on it) could have so many different connotations that I might not be Understanding it correctly.
"How much?" has a very straightforward translation in Irish - "cá mhéad?" (or "cé mhéad?").
The fact that "how much is it worth?" is semantically equivalent to "what is it worth?" which is semantically equivalent to "what value is on it?" doesn't make "how much is it worth?" an accurate translation, because you have chosen to change vocabulary that doesn't need to be changed, whereas "what is it worth?" at least retains the "what" part of the original question, and only changes the "value is on it" to "is it worth"? to make a more idiomatic phrasing in English.
"Cá mhéad is fiú é?" is "How much is it worth?"
I do the traditional DL translation into Hiberno-English (What value is on it?) and it gets rejected! I try How much is it worth? and that gets the flick too!
What value is it? seems unsatisfactory, somehow. I'd prefer to recast it as What is its value? but I imagine that would be rejected too...
"How much" is cá mhéad or cé mhéad, though you wouldn't typically use cá mhéad with luach, except perhaps in a sentence like "how much value does a new kitchen add to a house?".
"What value is on it?" isn't "Hiberno-English", it's just a word-for-word translation, though "what is the value that is on it?" would be a more accurate "literal" translation.
"What is it worth?" is the clearest idiomatic translation in English, though that can also be translated as Cad is fiú é?