When you dream that you are buying a piece of artwork, this usually means that you are a natural follower in life. You are great at being able to deal with a given set of directions and will never fail those that you are employed by. You will always impress people with your dedication to work and with the degree to which you are able to produce results that are required of you. However when it comes to doing your own thing or leading others, you do not excel in this department and often show issues with leading the greater group.
When you sell your artwork in your dreams, this shows that you are naturally expressive. You have a great talent at being able to get your feelings out in the open and you can explain everything you are feeling in such a way that the person you are talking to feels exactly as if your problems are theirs, and your successes as well. This is a rare talent and one that should be cultivated. If you feel you are capable of being this expressive, then maybe you should think about creating art in the waking world.
When you dream that you are an artist painting a picture, it shows your creative abilities. You are expressing yourself clearly and concisely and it also denotes your creative tendencies. You are naturally creative and tend to turn towards more creative methods of expressing yourself, eschewing the standard methods in order to give your work that extra punch that it needs in order to really succeed in changing the hearts and minds of audiences. You may not be a great artist, but you are a dedicated one, and that is also a talent in and of itself.
When you have a dream where you are the artist, you might want to pay attention also to what it is that you are painting. Some theorize that whatever it is that you are painting in your dream is a representation of your current state and your feelings. You are expressing yourself creatively, but an extension of yourself is the situations which you deal with and in which you are embroiled on a daily basis. You might already have a good idea of the status of yourself. But it might be kind of fun, the next time you have a dream like this, to look over your own shoulder and see what you're making. At the very least it could give you more ideas for a real painting when you snap back to the waking world.
If you dream that you are in the middle of an art gallery, this usually means that something very important to you is in the process of happening. Wither that, or you are in the process of forgetting something important to you that you ought not to forget. Do not let this warning go unheeded. Try to think of what it is that you need to preserve, and when you have a lock on it, save it in the mental vault for your records.