Which Boxster S would be a better purchase in the long run?

[Perfectlap]

Depends on the work done to either. My Boxster has 90K miles now. but I've put well over $12K in preventative maintenance, upgrades and repairs into it. All that repair work started around the high 60K mile range. Before that this car never made a peep. Also, high mileage engine isn't as tight as newer mileage engine. This is a sports car afterall, without some tuning, they leave some power on the table with time and age. Not a big deal if you're not a leadfoot meister. Either way, I don't see the point of getting into a high mileage water-cooled Porsche that's not had a very extensive list of repairs... suspension, clutch/IMS, cooling system, top condition, bodwork, etc. it can get out of hand quickly. And the time to do all that is time you're not sitting in your quickly depreciating mass produced Porsche.
Also, there's no such things as a $11K Porsche... that runs like a sports car.