Oh my gosh I payed so much more for mine a couple of years ago lol but here is a good link to WALMART of all places...
http://www.walmart.com/catalog/product.do?product_id=10824194
Pretty triple candle holder, actually... Normally you use tea lights which warm up the rock salt which increase the effect,... but DON'T burn the candles under your bed now lol!! But rock salt is rock salt and that is a cheap way to get true pretty Himalayan rock salt.... consider it dual purpose.... burn some candles at night, then put the holder underneath the bed after you blew out the candles...
There are a couple of other rock salt options (links) on the same site but this one is the most affordable...
Oh and definitely follow Cityhunter's advice. he's helped me out a great big deal! THANK YOU AGAIN, my friend!
P.S. Cityhunter, check out my doppelganger post - would like your opinion on that....
Hugs and blessings!