The description on the more expensive one is “LiftMaster Elite Series 1/2 HP Belt Drive Opener, MyQ WiFi Enabled, Battery Back-up, Timer-To-Close and Alert-To-Close, Includes (1) 893MAX remote control and (1) 880LM Wall Control, Model 8550W with 8’ Rail - Installed” The cheaper one is a “LiftMaster Contractor Series 1/2 HP Chain Drive Opener, MyQ Enabled, Alert-To-Close, Includes (1) 891LM 1-Button Remote Control and (1) 883LB 1-Button Doorbell Control, model 8065 with 8’ Rail - installed”
So part of the cost is certainly the install. Not sure about the difference though - I would imagine the install cost would be about the same between the two.