Those who have taken apart the electrical connections that connect a 220 v wall outlet to an EV find there is very little inside them. Other than some relatively simple safety features, they are basically a 220 v extension cord with the right connectors on both ends.

Why so expensive? At this point, its a small volume market and they can charge too much.

Source: What does an EVSE actually _do_? | Chevy Bolt EV Forum

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