Translation:How much is it?
Also, correct me if I'm wrong.
I think "how much" is exclusive to prices only. Measures have other interrogatives like "how long/short" for length, "how far/near" for distance, "how hot/cold" for temperatures, etc.
Exact translation for "how much is it?". It's about prices only, not quantities.
The same word written in katakana イクラ means "red caviar" (Search on wiki if you don't have idea about what it is, it's a common ingredient for Japanese sushi.)
Of course no one will misunderstand you if you want to ask about price in Japan, though :D
Would that mean if you're buying caviar you can ask イクラはいくらですか？ Because that would amuse me more than it probably should.
イクラかな。。。＝Hm... Red caviar, huh? いくらかな。。。＝Hm... How much is it, I wonder?
What's with that question mark? All other exercises I've seen featured the full stop punctuation 「。」 to terminate the question and relied on the 「か」as the last character to communicate a question.
It is optional. Originally, question marks were not part of the Japanese writing style (at least says so Wikipedia: "疑問符は元来の日本語の書法にはない"¹). "However, the question mark is very commonly used, especially in casual and creative writing and in manga."² I'd say Western influence changed the writing style. Now it's very common³. However, it is not usually used in formal Japanese¹¹.