Walmart has the Gain Dish Liquid Detergent (9 oz) for only $0.97. You can use a $0.50/1 coupon and get it for only $0.47.
Gain Dishwashing Liquid, 9 oz, $0.97
Use $0.50/1 Gain Dishwashing Liquid, exp. 9/30/11 (RP 08/14/11 R)
Final Price: $0.47
If you happen to be one of the lucky people living in the double coupon test market, you will actually get this for FREE!