Took barely two hours, including removing the wheel without air tools (damned compressor crapped out, not so easily fixed) and spending almost half an hour trying to find my 3/8ths socket tools. The wiring standoff bracket bolted to the valve cover, right next to the chassis rail was the hardest part.
Denso Wide Band O2 sensor with correct electrical plug: 154$
O2 sensor wrench: 11$
Nitrile gloves and anti-seize, probably 5$
Actually getting off the couch and being productive this evening...
...well, at least it is done now, and the CEL is gone. :D
Now to take it in for timing belt later this week, before a road trip this weekend.