I am 100% in Steve Tinker's camp. Read above about "Thinking about buying a Boxster". Do your research . Try several cars. Early cars are cheaper and I do like the low mileage aspect because accessories have less wear on them.
You cannot run a Box for the cost of running a Miata but then these two cars it is like comparing apples to oranges. Plan on spending $1500-2000 a year.
Ask for receipts for work done. Don't rush to buy one and of course get a PPI done.
Accident damage etc?
Cheers, Guy.