SAN FRANCISCO (AP) — An island offering a secluded beach, promises of great fishing and stunning views of the San Francisco skyline is up for sale — and at a discounted price.Red Rock Island, a 6-acre mass of rock tucked away in a northern part of San Francisco Bay, is now being offered for just under $5 million, Realtor Steven Higbee said. The property earlier this year was listed for $22 million.Mineral rights for the property, which Higbee says contains manganese in its rocky outcroppings, are negotiable.The undeveloped island has been on and off the market for years. Higbee said he advised the owner that the best way to move it was by “whittling away at the price.”Dishing out a few million dollars for a 5.78-acre property — especially one with no house or other structure — is not for everyone.