Selling:

Stacks of Slimeballs@$300 or $5 each.
Music Discs@$70 each, or $680 for all ten (availability is not guaranteed.)
Ender Chests@$250 each

Buying:

any unused diamond pickaxes with at least efficiency enchanted, preferably with unbreaking if at all possible.
any unused diamond swords with looting on them, preferably with a high sharpness too.

Stacks of Diamonds@$2,000 or $31 each.
Stacks of Blaze Rods@$450 or $7 each.

leave a message here if you're interested or just contact me in game.

everything is first come, first serve so if someone else gets to me in game first to buy something or sell me something I'm gonna go for it of course.