You're going to get a lot of different opinions
, but here's mine:
Without more info, it's impossible to say.
Here's why: You can buy a
NICE CBII for about 6K. If it's average, figure you'll have to do interior ($500-$1000), paint ($1000-5000+, depending on how nice you want it), then there's the mechanical end, plus all the little stuff that's missing/worn out/aged (valve stem seals are notorius for flaking and packing the oil pump/pickup after 25 years).
If it's complete, got a decent original interior, and under 100K miles, I'd say it's worth maybe $2500-$3000 (assuming it's going to need paint, because it will). If it needs interior, mechanical, missing parts like front spoiler and valance, etc; it's worth as little as you can get it for.
I once bought a V6/4 speed Cobra II that was missing only the front spoiler/valance for $150. Obviously, it needed everything, but it was a real CB.
Of course, there is always a larger group that want to buy into a project car than there is for finished cars (less cash up front), so the price will likely be a little higher than it's real worth.