If I remember correctly, with the Macbook Air it will have to be '"that's not right...", and grabbed another Macbook Air, and started migrating my data, etc, etc...'
Nope. Had a battery replaced in my 2012 Air recently(only because a clip separating the battery from the case broke,not because of the battery life) and it took 30 minutes to get it done at an Apple Store.
The RAM is the thing with Macbook Air's that permanently soldered to the system board. Everything else is difficult to replace due to the form factor, but still replaceable.