How much is a 1918 cancelled 3 cent stamp worth?

Answer 1

There were many 3 cent stamps during this time. Without a better identification, it would be hard to know what the value may be. There were so many different varieties that identification during this time frame is very difficult.

You need to fully identify the stamp, including knowing the catalog number, perforations, watermarks, condition and other factors. If you look it up in the catalog there is a price listed. That price is what a buyer should expect to pay a dealer for the stamp. If you are selling, you should consider yourself lucky if you get half that amount. Look for special markings. Stamps on envelopes can be worth more, particularly with picture cancellations, First Day Cancellations and special locations. Find a philatelist and ask for more information!