Value Village, 4618 14th St. NW (829-5728) and 5550 Kenilworth Ave., Riverdale (277-8179). Value Village is a vast, one-room department store, a maze of racks overloaded with secondhand clothes, shoes, drapes, bedspreads, dishes and bric-a-brac. Furniture and appliances crowd one corner. Value Village may be the last bastion of The Bargain, a place where a nickel still has buying power, or, as manager William Benton likes to believe, "a dime spends like a dollar." One shirt may go for a nickel, a suit for $6, a child'd raincoat for 50 cents. The mind-boggling prices are possible because all the merchandise is donated, and is sold as is. Proceeds go to the Village's parent organization, the non-profit National Children's Center for retarded children. Successful shopping here depends on what buyers are looking for and what other people are giving away. It may be apparel that is outgrown or outmoded but still in good condition. Some items may be coming apart at the seams, but pieces of material or buttons can often be salvaged, or appliances rebuilt. Donations, which are tax deductible, are picked up free of charge (call 261-3868). Anything is appreciated. Says Benton, "If it's an item that can't be used, we sell it for rags."