They're not really worth it, no. The main things to get are the kaisers and maybe 2nd copies of the ~2k atk eidolons. 2nd Tiamat's nice to have for the raw stats. 2nd Adramelech for Horus users. 2nd Icarus for Pazuzu users. 2nd St. Nicholas for Mana users. Maybe the SR eidolon limit break items if there are certain SRs you really want to raise for whatever reason (maybe you want a 4* Diabolos out of principal, or you have a Yamata no Orochi for which you just aren't getting more copies of via gacha), but those are low in priority.
...and wait, when the hell did regalia get added to the orb shop? That has to be a fairly recent update, right?