Long story short the only three types of cases you will ever need are a desk case for easy access (and display if you like that), a larger capacity case (if you are a collector and have a higher quantity), and a carrying/travel case.

If you don’t have very many pens, perhaps the only one you will need is a small carrying case!

Products mentioned:
Galen Leather 40 slot Pen case: https://www.galenleather.com/products...

TSL pen roll: https://www.baumkuchen.net/products/...

Here are some links to comprable cases that you might like (affiliate links):

Desk Cases:

(my fav option) 2 layered wood case with glass display: https://amzn.to/47Y2tm3
12 slot wood and glass display: https://amzn.to/4dBTurW
Luxurious 20 pen ebony wood case with glass display: https://amzn.to/47XaOGO

Large storage cases:

48 zippered pen case AFFORDABLE OPTION: https://amzn.to/3YbTZo7
20 zippered pen case: https://amzn.to/4eS3I8y

Carrying Cases:

Hard shell zipper case: https://amzn.to/3YbjZQD
Hard shell leather case (Galen leather dupe): https://amzn.to/40bNkvV
Moterm leather zip case with snap pocket: https://amzn.to/3XMOriE
Pilot pen roll: https://amzn.to/4dzhEnc
Leather sleeve cover: https://amzn.to/4eVpsAN
Luxurious Napa Leather case: https://amzn.to/4ertb9c