The DBGVC stands for "die cast model B, centrifugal governor, vertical mount, clockwise" as I recall.
All the parts come to around $50. For a first timer with a tech manual - it's easy to spend a full day on it. To a person with experience - 1 to 2 hours.
It is no more complicated that rebuilding a Rochester Quadrajet carburetor. Not easy but not that difficult either if careful. No special tools needed other then one special wrench that will cost you $10.
Depends if you want a learning experience . . or just want it fixed and don't want to risk it yourself. A pump shop will not "rebuild" it. They will replace small parts and likely leave the major moving parts as-is. Typical charge is $400 to $700.