Q:

Is it better to buy this used car from Craigslist or from a dealership?

I was looking for a cheap car and noticed that I can buy a 2006 Toyota Prius with more than 200k miles off from Craigslist for $3500 or the same Prius with a little less than 100k from a dealership for $10000. Most people I talked about the subject said that it is better to buy off a dealership than from Craigslist, although they didn't know the details other than saying that a 200k miles car will certainly give more maintenance than a 100k miles car and that the dealership will give warranty. I drew a table to calculate the possible expenses:
Assuming that the car will be driven for 4 years and 50k miles and both will be insured for state minimum:
200k miles Prius off Craigslist

Price of purchase: ($3500)
Registration in California: ($367)
Expected maintenance: ($6000)
Price of resale: $3000
TCO: $6867

100k miles Prius off dealership

Price of purchase: ($10000)
Registration in California: ($890)
Expected maintenance: ($3000)
Price of resale: $6000
TCO: $7890

Thus the cheap Prius seems to be still a good deal. Am I mistaken somewhere on the reasoning? 

A:

I do not think you are missing much.  One thing you have right is low cost cars depreciate almost nothing.  One thing you are missing is your satisfaction index.  Driving a 200K car for 4 years requires a bit of motivation when your friends are driving new cars.  Typically you need a larger goal to keep you focused.  That might be saving money, getting out of debt, or obtaining an education.
Buying a car from a private party, Craigslist is only one source, can save both parties money as the "middle man" is cut out.
If you have the ability to do so, one can save a lot of money by doing your own brakes.  The info is up on youtube, and I typically "earn" between 100-300/hour doing this work myself.
Most of the time warranties do not pay off.  At the core, they are insurance and insurance companies are in the business to make money.  If your car is likely to need repairs a policy may be unattainable or very high in price.

