This information was shared by our AC member Anne A. Thanks!
"...students with financial need (or other qualifying factors) can apply for fee waivers for free SAT and reduced-cost AP tests. In addition to these resources from the College Board, some districts have their own fee waiver forms for qualifying students, which drop the remaining AP fees even lower."
SAT fee waiver information (includes subject tests, score reports, college application fees, and more)
AP fee waiver information