Thought I would just post and say that I had trouble with the use of "$" in a field. It showed correctly through the form however when the email went out it would just be blank.
Example: Shirt ($30)
when confirm email: Shirt ()
So its perhaps its being mistaken for a variable?
To get around it, in the field I used unicode.
Example: Shirt ($30)
And that seemed to of fixed my issue. Though when you save the form it transforms that unicode into the $ sign.