Before you buy Ambien online for Insomnia, know its strengths like Ambien 5mg, Ambien 10mg, etc. two forms of Ambien sleep pills are Ambien IR & Ambien CR. If you're looking for a good deal on Ambien, your best bet may be to purchase it online. Many pharmacies sell the drug for much less than the price at pharmacies in brick-and-mortar stores. However, be aware that some of these websites may not be reputable, so be sure to research any given site before buying.