Collecting stamps is one of the most popular hobbies all over the world that has started since 1950s. To know the value of the stamp, there are things to consider such as:
Condition – the stamp which has the same state as for how the Post Office issued will have a higher value.
Colors – stamp should still have bright, fresh and original colors.
Date of issue – stamps issued before 1960 has more good historical stories.
From which country – countries where postal deliveries were infrequent and fewer commands a higher price.
Denomination – stamps with denominations above one shilling are worth more because of its rarity.
Completeness – a stamp with missing design or damage will devalue its worth even if it is extremely rare.
Used – unhinged stamp worth more as its original gum is still intact.
Contains rare error – when a stamp is printed in error such as stamp design, missing colors or features, it becomes noticeable and rare that makes it more collectible.
Perfection – stamp with perfect edging and perforations values much higher.
To understand more about getting a stamp appraisal – read this guide – https://www.westcoaststamps.com/stamp-collection-appraisals