Care to share your plan and the math behind this statement cause it sounds completely unrealistic? or what does your 'all' mean because it can be really subjective.
For getting "all" the good old items, the new items and upgrading them is around 130-170k flowers. Even if you own all the explorers in game since 2011 and have them all booked to the max and keep the flowers farms running with the best buffs (including new tree and 2 friend buffs) you can barely get half of whats being offered in shop. If you were thinking of getting the rest of the flowers by trading then Sandycove must be really special place if people are willing to trade away their flowers in such quantity's as everyone else will be buying them too.
The event will be absolutely dreadful for many people who wont bet able to run the farms with friend buff or don't have a massive army of explorers. The actions made for
the event make it seem to be clearly a cash grab push compared to all the previous events in the game history.