You can frag:

[li]r1-99 (restockable items) [li]r101 (retired) [li]115 (melody items) [li]150 (special items) [li]160 (game prizes) [li]175 (holiday items)

[edit] HA I'm dumb. Yeah, they do return a crystal, but it's only a 0-1. I forgot there was the chance for 1. The higher end of restockable rarities is 1-2, so you for sure at least get one. MY BAD