I thought about painting, but like you said, it just wouldn't be the same :) I'm not sure why exactly, but I would like to have a pre-printed one. The humor/novelty aspect, I suppose, of having the product with her name on it instead of just painting her name on a box.
If I can't find a printed box I'll likely go find something else - there is a nice supply holder at the local farm and garden shop that I will likely go for otherwise. It's much more expensive though. :)
EDIT: Also tried Craigslist/Kijiji. None there either :p