I would like to point out that "seedium" plants are occasionally subject to a glitch whereby a player buys the plant for 250 seeds then immediately leaves the game then goes back to the plant in the almanac and (usually) the plant has unlocked and the 250 seeds are still available for upgrading (to level 5).
Still a very expensive way of buying a plant as Humplemann says, and making them time locked then selling the seed packets for gems is extracting the urine from players.
I'm still waiting for the "Humplemint" to be announced.
EDIT: the "WHAT PLAYERS WANT" post is still going if you want to leave short and to the point changes you'd like to see in the vain hope that someone in authority might one day read it and do something before the last spark of my optimism has been snuffed out.