What's a good, low-maintenance option for a small herb garden/grow box?

[Backseat Driver]

5. FWIW, my tips: Don't put (pepper)mints in the ground - invasive spreader!

Lemon balm is in the mint family and spreads invasively as well. With a 3 ft height, it will spread (seed and root systems) and will throw shade on anything planted behind it. Has medicinal effects and used in cosmetics, but in the same family as mints (see above).

cheap container or pot to hold dirt - nursery transplants.

Lavender seeds take a long time to germinate, so likely too late to start. Larger mature plants are perenniels in 6b and somewhat drought and soil hardy - mulched, they will overwinter fine.

I've always had trouble with cilantro (drys easily and not stable in stormy winds).