I read an article which stated that older GA aircraft are actually being turned away from some maintenance shops due to insurance liabilities.
http://www.aopa.org/whatsnew/newsitems/2007/070108maintenance.html
This article mentions the "deep pockets" for attorneys to attack. Anyone wishing to identify the root cause of the high expense of aviation (as well as numerous things in our society) could simply settle on that one little word..."ATTORNEYS."