Not sure if I agree with Ethier. He's been worth his contract so far.
Last year he made $13.5 million (first year of the deal) and was worth $14.7 million, that's not too bad BUT if you assume standard aging and WAR loss he's gonna lose like .5 WAR per year at this point. So you're looking at
2013 2.9 $13.5m
2014 2.4 $15.5m
2015 1.9 $18m
2016 1.4 $16m
2017 .9 $17m
2018 .4 $17.5m (team option, $2.5m buyout)
Total: 82.5m (I'm assuming he gets bought out for 2018)
The cost per WAR of a RFer from 2007 to 2011 was about $5.7m (
http://www.fangraphs.com/blogs/positional-differences-in-the-price-of-war-2/)
So if you use that as a reference point he's roughly going to be worth the following the next few years:
2013 $14.7m
2014 $13.68m
2015 $10.83m
2016 $7.98m
2017 $5.13m
2018 $0m ($2.18m but I'm assuming he gets bought out)
Total: $52.32m
Difference: $82.5m - 52.32 = 30.18m of lost money.
Inflation will offset some of this but I mean its still an awful contract.