TP-Link Switch $39.99 - $7 Amazon Coupon = $32.99
https://www.amazon.com/gp/aw/d/B01EZV35QU/ref=pd_aw_sim_451_2?ie=UTF8&psc=1&refRID=7BJMQ9DPA3H5AD1S59CA&th=1
TP-Link Outlet w/Energy Monitoring $38.92 - $7 Coupon = $31.92
https://www.amazon.com/gp/aw/d/B0178IC5ZY/ref=pd_aw_sim_451_2?ie=UTF8&psc=1&refRID=7BJMQ9DPA3H5AD1S59CA&th=1
These are not directly compatible with SmartThings. They do however integrate directly with the Amazon Echo. They have been integrated with a secondary server here:
Also there has been a comment that these may get future integration: