I just picked up a 2007 EL Limited with 100,400 miles for $19,200 after trade in. Had a Car Fax report with it that showed a good record of maintenance and no accidents. Also, previous owner had a business and put lots of highway miles on it, which is good, not all city stop and go driving. Bought it from the dealer who also serviced the vehicle. I traded in my 1997 EB which had 252,000 miles on it, so, my feeling, you take care of your Ford, it takes care of you.
Prior to this decision, I did a lot of on line research. Found similar EL Limiteds or EBs, in the 2007 - 2008 year ranges, with 40 - 60K miles on them were running $26 - 28K+ to buy. So, my thinking, I seriously doubt I will be dumping another $6 - 8K, outside or routine maintenance requirements, into this new one given my experience with my previous Expedition in which I still had my original engine, trans and all.