Question Birdcage rust

[Tom1976C3]

Looking to buy this 1976 C3. This car looks good 80,000 miles tack does not work, emergency break doesn't work, seat needs repair.
Car appears to have birdcage rust (picturs attached).
asking selling price is $10,000. Is it worth buying?

 

[E-TownC8]

Looks real purty from the topside, but I would suggest getting a good mechanic familiar with older 'Vettes to put it up on a hoist and tell you what you've got.
You didn't say where you are, where this car is, where this car spent its life, and was it driven in the winter, or did the salt air get to it - it's almost 50 years old, so if it's never undergone any restoration, there's likely a lot of bad news underneath.
I don't know what a "birdcage" is - maybe you could clarify what we're looking at in those photos.
Tach should be repairable - GM original parts, or you can go aftermarket. Or you might get lucky and its just a broken wire.
The internal drum parking brakes were a common problem - new cables and a teardown to clean up the rust and install new shoes, parts required.
Reupholstering the seats - add it to the list... Cha-ching.... And have a look at the rest of the interior - what else needs work that you'll eventually want to fix.
Is that asking price in US$ or CDN$?
Is the car currently licensed? Do you need an inspection/certification to insure / license it if you're buying it from out of state/province/country? They are usually pretty fussy, the car may need a lot of work just to make it roadworthy.
The carpets / underlay look rough - water damage? rotting? Have mice gotten into it?
You should consider resale value - this ain't a '67 big block car - C3's were a dime a dozen, you could spend mucho $$ fixing it and have a hard time getting your money back later on.
Unless you're planning on doing a lot of work yourself and have the skills/tools/etc., you may be looking at a lot of $$ to get it roadworthy - a good inspection will tell you where you stand.
That's a long way of saying "Probably not"
- from a '79 coupe owner - bought in 1980, got tired of fixing it and sold it in 1994 for $5,000 and never looked back