I used also 40 gems, to buy 2 Swamp Traps. I did this when I was at level 6.
The 2 traps gave me 2 Monsters and these gave me 2 + 4 cattails.
So I could craft the Swamp Kitty, and this one gives me 30 Water Lillies every day.
And this can help to go to the 1500 nedeed. I hope I'll get the frog .
Good luck to everybody