rebuilt carb from parts store vs NOS carb

i need a new carb for my slant 6, so performance isnt the issue just need something fresh. what are the pros and cons of getting a rebuilt carb from a parts store vs buying a NOS one off ebay or something. Theres some NOS enconomasters on ebay that would work or a rebuilt 1945 holley from the store, prices are about the same, lets hear it! lol

What I would be worried about is if the nos one was dried out from sitting for so long. How about rebuilding your old one?