Honestly, I would say not at all. You can get much more for the same price (granted you would look either CPO or used private market). Plus you are going to deal with a huge chunk of the depreciation value in the next 1-2 years.
Now if you are so certain on having AP2.0 then go ahead. However, I don't think AP2.0 will be useful not until the next 2 years or so.
So you could buy an AP1 car, then 2-3 years from now sell that one and upgrade to an AP2 car when full autonomy is out there and working. Plus who knows if there will be like AP3.0 for all we know in 3 years.