CANSHN via Amazon has select iPhone Clear Cases on sale with prices starting from $2.52 when you apply the corresponding promotional code listed below at checkout. Shipping is free with Prime or on orders $25+.
iPhone Xs / X Clear Case $2.52 with code EZCWAIRS
iPhone 7 Plus / 8 Plus Clear Case $2.52 with code Z2ZNXCNY
iPhone 7 / 8 Clear Case $2.80 with code OSGFOW2I
iPhone Xs Max Clear Case $2.52 with code 2PQV3I9B