I'm from Chile and last year I bought here a bike from a guy who travel from L.A. to here. Here in Chile you can't make legal a bike if you imported it used, but the buyer can make some legal arrangements with lawyers to make it legal. I'm doing that right now, is not easy, but is possible.
the thing is that you CAN sell a bike here in chile, but the buyer can't use it on the street. You can left the country by airplane without your bike, I know that because I left the guy in the airport... no problems at all.
If you sell your bike here at a good price, you will sell it, I can help you on that, and if the price is good enought for me may be I'll buy it too!!!
I hope this can help you and sorry for my crapy english
Santiago-Ushuaia-Alaska Right Now!!!