So if 'bao nhiêu' is placed after the object, it is asking about cost? And before the object it is asking about quantity?
In the tips and notes giá is used with bao nhiêu to ask for price....but I haven't seen it used in the course yet.
This is an incorrect assumption. The meaning depends on the context of the sentence (and the main verb if there is one). In this sentence, you could swap the order and it would still mean "how much". (Just like in English, you can say "how much is your skirt?" or "your skirt is how much?")
Here, the subject is singular. Barring any main verb context, it would be awkward to mean "how many is your skirt?"
I don't think so, the verb có is missing: Bạn có bao nhiêu cái (áo)?
How much IS your skirt sounds like we want to buy it from you. We're more likely to ask how much was it?
It sounds like the recording says "cáy váy HE của bạn bao nhiêu", like the word "he" is placed in the sentence.
I also hear like the sentence started by "t". Played again and again and a hear a t instead of a c
The translation "how much was your skirt" should be accepted as the skirt is a possession that was purchased previously. Thêrefore past tense would be applied. Using is would only apply tô asking a shop assistant and in that case it would be " this skirt" not "your skirt"