+1 to chests atleast

 

-1 (to chests and shulker shells).

Chests are incredibly easy to make -- debatably one of the easiest. The block shop already sells all wood logs, so the only part you need to do is convert to planks and then to chests. Wood is easy to get -- go to /warp pixel, wack a few spruce trees, and you can have yourself a few stacks of logs in no time. Chests can be produced in bulk very quickly and very easily.

I don't see a huge issue with shulker shells nor a huge demand for them -- I see there are 2-3 double chests of shulker shells available, which can make a good amount of shulkers. Also, shulkers are different because shells are actually obtainable with shulker spawners -- you can just slap one down in the mining world, level up your swords mcMMO, and enjoy the shells.

(Note that I am also a proponent of blockshop being strictly for blocks that are absolutely rare / unobtainable, the rest should be up to the player market.)