Interesting...I may have to write an article on this
I did a quick check and there is a useful site called
Word IQ where you can place a word in their search engine and it will give you the meaning of it in a dream. For example, a search for "coin" got the following result:
To see gold coins in your dream represents success and wealth. Silver coins represent spirituality, values, and your self-esteem. Coins in dreams can also suggest missed opportunities.
Searching other sites is is readily apparent that there are a wide variety of interpretations of money and dreams with the meanings as variable as the meaning of money in real life. There also seems to be disagreement among dream interpretation authorities of its meaning...some of the definitions for the same symbol are complete opposites depending on what site you visit.
This certainly is not my area of expertise, but it is an interesting subject...