I've taken the IV therapy course twice when I was an LVN, but this was in the Dallas/Fort Worth area. I did not have to pay for the classes because my workplace sponsored nurses who wanted to attend.
See if Omnicare or APS (American Pharmaceutical Services) operates pharmacies in your area. They tend to have nurses on board who teach the IV therapy courses. If a place of employment is not sponsoring your attendance, the IV therapy course could cost several hundred dollars.