If you are considering a graduate program, you may be able to receive a waiver on your graduate admissions exams, like the GRE and PRAXIS.
GRE Fee Waiver
ETS, company that administers the GRE, offers a limited number of GRE Fee Reduction Certificates on a first-come, first-served basis that are available for college seniors and unenrolled college graduates who meet eligibility requirements. A Fee Reduction Certificate may be used for one GRE® revised General Test and/or one GRE® Subject Test. Individuals meeting the eligibility requirements will be required to pay 50 percent of the full test fee.
Additional Details: http://www.ets.org/gre/subject/about/fees/reduction/
Fee Reduction Certificate: http://www.ets.org/s/gre/pdf/gre_fee_reduction_certificate.pdf
PRAXIS Fee Waiver
Fee waivers may be available for college students who meet all eligibility criteria. If you qualify for a fee waiver, the test fees for up to three Praxis I® Pre-Professional Skills Tests or one Praxis II® Subject Assessment may be waived.
Additional Details: http://www.ets.org/praxis/about/fees/fee_waivers/