Seems like a pretty solid deal.
As far as 3-4k cars go, intuitively they would always be cheaper than a 8k car but not always so - the total cost of ownership needs worked out. For example, for my driving, including fuel, a monthly stipend for repairs, insurance, purchase price, estimated sales price, the monthly cost for my 02 Focus with 115k miles and a 12 Focus with around 20k miles is almost identical. How? Better mileage on the 12 Focus and good resale as well, and lower maintenance costs (offset to a small degree by higher insurance costs). So the car that costs 3x more barely costs $10 / month to own over a span of 36 months. Additionally, there is no measurement for reliability and safety based on the newer vehicle but if you can figure a value for that, it would further equalize / tip the scales. I am not advocating for any particular choice, just trying to show that cheaper initial cost doesn't mean less expensive overall cost.
I would wager that the Fit would be worth about the same 8k after 30 or 40k miles are added on.