I've just discovered the term "threshold earner".  It makes good sense to me so I'm sharing it.

A threshold earner is someone who seeks to earn a certain amount of money and no more. If wages go up, that person will respond by seeking less work or by working less hard or less often. That person simply wants to “get by” in terms of absolute earning power in order to experience other gains in the form of leisure—whether spending time with friends and family, walking in the woods and so on. Luck aside, that person’s income will never rise much above the threshold.

I much prefer "getting by and doing interesting stuff" to "getting more stuff but not having time to do what interests me."  but I didn't have a neat way to express that before - now I do ."Threshold earner". I like it.

The first reference I saw to this was  via a tweet from Tessy Britton - RT @karlwilding Are you driven to maximize income or maximize autonomy and time for satisfying creative work? economist.com #fab!

The tweet led me to "Unemployment and jobs - Work for post-materialists" - http://www.economist.com/blogs/democracyinamerica/2011/07/unemployment-and-jobs
 
That in turn led me to the post "The Inequality That Matters" http://www.the-american-interest.com/article-bd.cfm?piece=907 - which is where the term seems to have originated.

Both are posts worth reading.