Originally Posted by Myrdin

HH, Bro > men age like wine - the older and more succesfull you get, the more desirable you will be.

Anyway - My advice is: dont go around buying Fgems for this - its not worth it. Lets say you spend 50 buckf for the gems. Instead you can spend it on a Step up Gacha with a 6* girl at the end, or another of those deals that pop up time to time and are actually worth it when compared to the other more expensive ones.
OR
Wait for the Gacha that gives you both the girl and an extra dressbloom ! Sure they are expensive as all hell (usually 60+ bucks from what we´ve seen so far.), but if you are willing to throw the money away for flower gems to get the dress blooms, this is more economical in the long run (doesnt make it any cheaper though).

It's just, that at some point, there's no real point to getting more rainbows, and you'd rather see the rainbows you have improve. Although buying FGs for these dressblooms is still expensive to accomplish that, and it'd probably be cheaper to wait for a step-up gacha which has dressblooms as side-catch.

I must say, I'm actually tempted with the current offer, to get 2 more equipment slots for Acacia, and to unlock the second equipmentslot for one of several girls with personal jewelry.