Toyota Avalon-beater or restore?

I have a daily 4runner thats I'd like to keep low, in both mileage, gas, and insurance. Recently my long time friend is selling his running/driving 2011 Toyota avalon he's had since new for $1700, 257k miles. 80% percent of that was highway miles, as he drove interstate for school/work. It doesn't have A/C, and we live in the south, so it would require 1k to remove the dash and do all that.

My conundrum is that although they had a family friend work the oil changes, brakes, basics etc. consistently, Im worried about the cost of the non basic maintenance, like trans fluid, coolant, timing belt, etc. I like working on my cars in rotation, so if I do the Trans fluid of one I would do the rest in the month, same with coolant, etc.

If I buy this car, is it worth it to see if I can do minimal work/treat it like a beater to save money, as nobody else would likely buy a car at this mileage: or treat it like a car I plan to keep for 5 years and look at the trans fluid, timing chain, etc.