If you have some time and space to work on the car, and have the tools, I would. It's not rocket science and the instructions here show every step with pictures. However, if you don't have any mechanical confidence or experience, I would think twice. I rent the special timing belt and camshaft tools but you would still need various garage tools.
73k is low enough to be in good shape but high enough so that cam wear could be showing up soon. It'll also need a timing belt soon. Take a look at the 2005-6 buying guide, the 2005.5 has some extra features not found on the 2006 depending on the trim so it could be a good buy.
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