Unlike many services where consumers can find out how much a service costs before having it performed, tax preparers often leave clients wondering how much of a hit their wallet is going to take. A 2010 "mystery shopper" investigation by the National Consumer Law Center (NCLC) and other organizations found several instances in which tax preparers evaded questions about the costs or refused to provide an estimate. According to NCLC attorney Chi Chi Wu, this lack of transparency creates opportunities for everything from additional fees and fraud. Most tax preparers say they cannot provide an estimate until they review each individual's needs and circumstances. While many base their fees on the number of forms, the amount of time needed for each form varies widely. In order to avoid paying too much for the service, consumers should request a free consultation, stay away from refund-anticipation loans, consider doing their own taxes, and look into free sources of tax preparation assistance.