I have an extensive snow globe collection, and I have bought snow globes off eBay. One had a bubble at the top (when the description claimed it did not). As a collector, I would be wary of buying a snowglobe without the box. How would you ship it? Even Craigslist would be difficult, because how could someone come pick it up and take it home? I suppose you might get lucky with some other form of shipping material, but I don't take mine anywhere without the original boxes.
Most new snowglobes can be purchased for $30-$100 dollars from Disney. Rare or highly sought-after ones can go for more. It also depends upon whether or not they are musical, light up, have movement, or any combination. I also would never consider buying unless it came from a smoke-free home.
Good luck.