I believe it would be financially better for the server if leaves were to be able to be sold on the /Shop.
The leaves I would love to be included are as following
-Dark oak leaves
-Flowering azalea leaves
-Nether Wart block (Technically leaves but in the nether)
-Warped nether wart block (Also technically leaves and also in the nether)
And my suggestion for how much they could be is around $1.50 to $2. Because I believe this would financially improve the server quite allot and help players out and getting closer for everything to be on the shop:)