As you try to hold onto your home, the pitch comes in an official-looking envelope. Since property taxes are based on market values, which are way down, hire us for a fee–$179 in one recent Los Angeles-area mailing–to file a request for a reduction in your property valuation. Legal, but sketchy. That’s because this usually can be done for free using a form downloadable from the local tax assessor’s Web site. In many places–including Los Angeles County–the assessor already automatically reassesses likely candidates for reduction.