What’s the value of this ??

Prices will never be crazy on those old carburetors as long as the similar Edelbrocks are as reasonably priced as they are. Your market for that type thing is very, very narrow, expecting premium price. You're looking for someone who has the exact year and model car that particular number came off of that's missing theirs, or wants one rebuilt to replace theirs. Most people simply pull the numbers carburetor put it on the shelf and put the Edelbrock on. I would suspect $200 would be an absolute maximum.