So basically both rainbow gacha deals are rolls where you can get a random rainbow, not a ticket where you can choose?
10000 deal guarantee 1 random rainbow + bonus thingy.
5000 deal only guarantee gold with chance to get a rainbow + bonus thingy.
This deal won't give any ticket, but if you buy all 10000+5000+3000 you will get 300 rainbow coin.
300 rainbow coin = 1 rainbow ticket.