One thing I have learned in my years of stamp dealing is the importance of quality.
Every stamp is not perfect. Some stamps have minor faults such as a light crease or a tiny thin. Some stamps have major faults such as heavy cancellations or missing pieces.
Damaged copies of inexpensive stamps and even moderately expensive stamps just don’t sell. Period.
When I started in the stamp business, some of the material I started with was faulty. I tried to sell it, but there were very few takers. That $5 catalog value stamp with a heavy cancel or a missing piece that was priced at 50¢ just didn’t move.
Collectors generally try to collect stamps that are the most pleasing in appearance.
When possible, collectors prefer mint over used copies. For common and inexpensive material, I sell many more mint stamps than used stamps.
When the price becomes too steep (which differs from one collector to another), they prefer sound, used copies with average to light cancellations. As the catalog value increases, collectors are more tolerant of faults. Even then, the ugly ducklings have to sell at huge discounts.
Whenever possible, I think collectors would rather spend $200 for a copy that has small faults (such as a thin or crease). How the stamp looks from the front is very important to them. They would rather spend $200 for a copy than $50 for a copy that has a heavy cancel or a missing piece.
Yes, there is a segment of collectors who look to fill album spaces by Scott catalog number as cheaply as possible. They’ll accept the ugly ducklings. That segment is very tiny in my experience.
Most collectors will accept small faults on the most expensive items in their collection as long as the stamp is visually appealing. This segment of collectors is very large.
Some collectors are very condition conscious. They insist on never hinged stamps. They won’t take a faulty copy, no matter how cheap the price is. Every stamp has to be perfect. This segment of collectors isn’t trivial, but it isn’t huge either.
When building your collection, I encourage you to choose the stamps that you like, but don’t overlook quality. If you’re going to build a collection of ugly ducklings, there is nothing wrong with that. When it’s time to sell your collection though, don’t be surprised if there isn’t much demand for it.
If your collection has visual appeal, there will be more buyers for it, especially if you’re able to limit the faults to very insignificant things. These collections move faster. Dealers are more interested in buying them.
I have repeatedly said that demand is everything in stamp collecting. That is still very true. In my experience, quality and demand go hand in hand. The better quality your collection has, the more demand there is going to be for it.