The shop is small because its suppose to challenge players to smelt and craft items, for example, there is clay blocks on the shop but you need to smelt them to create harden clay after that you use a dye and make stained clay blocks, another example, diorite is crafter with 2 cobblestones and 2 nether quartz,
I do agree that they should add nether quartz.
You can hit the grass with bonemeal to create flowers if you didn't know.
Animals stack to create less lag on the sever.