Thumb Score: +18

Amazon [amazon.com] has Klein Tools RT250 GFCI Outlet Tester w/ LCD Display on sale for $19.98. Shipping is free w/ Prime or on orders $35+.

Lowe’s [lowes.com] has the Klein Tools RT250 GFCI Outlet Tester w/ LCD Display on sale for $19.98 with free store pickup.

Great reviews on this outlet tester.