Don't know if this will help but we were at WDW last week and we saw a huge bin of mister fans at the new Wal-Mart. So if you can't find one at home try there. The bin was right near the entrance and it was huge. I think they were around $5.00. We saw lots of people in the parks with them. We just used a very small one from The Source. It was much easier to carry and fit in my purse. We just had to fill it a few times a day from our water bottle.
If you have a Linens 'N Things store in your area, check out the clearance section. I just found some today (identical to the ones sold at the park except for the Disney logo) for $2.00 - Discounted from $7.99.
