Do Certification Test Costs Limit Interpreter Supply?

NewbieTexasTerp is waiting nervously for an interpreter certification test that could determine her future as an interpreter. However, as NewbieTexasTerp points out, the cost of the certification test is such that if the test is not passed on the first try, she can't afford to try again. And if she can't afford to try again, the deaf community loses out on a potentially good interpreter.