You obviously haven't looked at the Cure album reissues. The box set contained all their b-sides and released rarities and a couple that were unreleased. The new album reissues contain the remastered album on one disc and an extra disc of mostly unreleased tracks like demos, live versions, and outtakes. For instance, the Faith set contains Carnage Visors, which has never been officially released on CD before and disc two contains fifteen additional tracks. You can get them cheap at BMG Music Club btw.