Inspired by all-in-one rolling & carrying solutions like thing:2796316 but wanted fewer moving parts & a more secure closure.
Remove the lid and rest the tower inside it to create a rolling tray.
This version is just big enough to hold a single typical (d4, d6, d8, d10, d20, 2 percentile) set.
Lay the lid flat on its "back" for printing, but print the tower upright. You will need a support for the lower aperture but the ramps inside should print without supports (so set your minimum overhang to 50° or more).
Very little infill on the tower—10% should be enough to ensure that the top prints correctly.