2000 Base 73k - $11,000 - Good deal?

I would still advise you:

1) Get a PPI
2) Either get the Warranty (cost-in-use is about 13 cents per mile) or immediately put $5 large in an account for future unscheduled maintenance- you don't want to be Boxster "rich" and repair "poor" after the purchase
3) Make sure you have a handle on your car insurance costs before you buy