Board Thread:Question and Answer/@comment-29547733-20161123105452/@comment-29349735-20161123110003

You get approximately 110 tickets per 3000 jewels for Premium Summon. This means that if you premium summon, you need 57k jewels for that 2000 tickets.

You'll need a bit more than 60k if you do step-up instead, but I highly recommend doing this if you're really aiming for the full Celestial Oracle, since Step Up will get you better summoned cards as well (plus, with a copy of the point booster, you're guaranteed to get T100 for LR Fenrir).

Summoning for it (over just one event) is obviously not recommended. If you are aiming for Celestial Oracle, it's better to spend 1500 tickets for Oracle Chair+Laurel, and use a mirror maiden to make up the missing ticket. It's cheaper by far unless if you need multiple copies of summon cards.