I dont even think it is rare. And agree the $400 would seem a more defensible price. (Im still unhappy that all the fuel retailers list the tiny $.009 to the right of their three digit prices. Like its going to affect local sales?)
On long drives, we lay a paper towel roll between the seat backs, for my elbow.
A long time ago, I made up an armrest for my Dodge Omni's. It easily pulled out so it could transfer to one of the other Omni's. It had a cupholder built in the front sized for the largest soft drink cups the convenience stores