Hi,
it didn't say when the ball is, maybe you've already got something, but little elizabethan sweete bags would be really appropriate, they were used as a sort of gift boxes at the times, but some were so fancily decorated people collected them as itself too.
Basically like small purses. Of course I can't make any beading or personalized embroidery at the price, but with matching to your ball theme colors colored fanciful fabric and small tassel they might have use after the event too as toiletry bags etc. people would remember the even every time the look at it later. You could slip a thank you note/wrapped candy inside as well.
But if you're still looking, I could make bulk of simple design sweete bags with your price range. Or, if you would have little gifts already, I can make little gift bags this shape instead of the usual rectangle wedding favor bag, but would have to lose the tassels and use cheap fabric that may not be so shakespearen to keep it under $5 a piece..
(I'd need to calculate the actual quote but with sewing the more you can make at once the cheaper one piece will be)
Unfortunately there's none available at my shop atm to show, but this is the shape, the upper edge has drawstring, size approx 15/20cm
http://img1.etsystatic.com/000/0/6050570/il_170x135.217404603.jpg
