I have a 1999 4Runner I love and recently found people in the US love them too, paying around $15,000 for a diesel conversion, truck not included. I could easily get about $5,000 more there than they sell for here and a nice road trip included. A 1999 model is over the 25 year limit for US imports so I don't believe that will be an issue.
When I lived in Mexico they were pretty firm about no exporting- anyone have an idea about the policy here?