Studies of existing best practices cannot determine whether the current "best" schooling practices could be even better, less costly, or more effective and/or improve at a faster rate, but we can discover a cost effective menu of schooling options and each item's minimum cost through market accountability experiments. This paper describes experiments that would create opportunities for market entry and a price system to signal cost and quality benchmarks (current minimum costs) to families and educators to produce information for policymakers. The entry-price system combination has a great economy-wide track record because it harnesses highly dispersed knowledge about schooling practices and exploits self-interest through opportunities to compete. States or school districts can employ one of four possible market accountability experiments to assess what families want from among the schooling options educators prove to be willing to offer and at what cost: (a) large tax credits or a large universal voucher, (b) school district vouchers, (c) competitive contracting out of school management, and (d) charter law adjustments. This paper describes and compares those four ways to discover a cost-effective menu of schooling options and how much each costs, certainly a key element of one of the biggest policy challenges of our times, drastically improving the performance and efficiency of our K-12 system. (Contains 1 note.)