save those dragonic eyes for better stuff... it's a waste to use them for anything in the shop right now...

as for gacha for SSR kami, you'll have your best chance at 10-chain gachas (like the magic jewel one for 3k jewels) cause you're forced to get an SR or higher....

given you have a 3% chance to get ANY SSR, you'll likely get an SSR (kami weapon or eidolon), every 3 to 4 10-chain attempts