1966 Buick Riviera 425 nailhead with ST400 switch pitch

I have the opportunity to buy a 1967 Electra convertible. First, what is
a price range for this year/model convertible if we are talking good
shape, all options working, no AC, 125K miles (repainted a year ago,
fair paint job)? The interior is original and in very good condition,
the exterior is fair, good chrome but some rust patching above the rear
wheel wells.

Also, I am not certain what I am possibly getting myself into in terms
of parts availability for a car this old. Is this model one that has
decent parts availability , or should I steer clear? I am looking for
opinions from folks who own or have owned this model, in the model year
from the middle to late 60's.

Thanks in advance for any info.