Manual vs standard: each has its advantages; I am not like the snotty Europeans who look down on autos. I do stuff with my right hand, and the low-powered/close-ratio standards I have had (old rwd Mazda GLC/323 wagon, current 85 Corolla, 76(?) Celica ST, Honda Civic wagon, Chevette Scooter) all required much shifting.
As to old cars, there are $500 bargains out there; but watch out too: paying big bucks is no guarantee of anything, I could regale you with tragic tales of woe about my F250 long box extended cab, and its electrics. Try steering that beast when it stalls. Or pushing it. (I like a car I can push... Have had to do so too many times, and always it seems while wearing runners, in deep snow or rain... there's boots in my trunk always now.) (Yay boots in the boot.)
On the other hand, blue book does not tell the whole story. Like when I bought the MPV I paid well over book value because it was in perfect condition (owned by a mechanic at a dealership.) Try to think in terms of amortised cost: total running cost over its lifetime: paying more up front to save repairs down the road is worth it, if you are not ready, willing, and able to fix things, and if you don't have access to a second vehicle for running around to fix the first one.