Next time, I'd like to fly into SCL and take a bus to Mendoza just to get the full sense of the Andean crossing. Has anyone done that? By Googling, I found someone's travelogue with pictures, but I never actually found a good source for schedules, etc. I've never been to Valparaiso, so maybe I could that to the mix next time, too.
Of course, you can just take a quick flight from SCL to MDZ as was suggested. Last month, I flew into MDZ from AEP. This would be kind of a pain if you're not intending to hang out in Buenos Aires for a while, because coming from the States you'd have to change airports from EZE to AEP.