I am going to go straight for the Poppy Pony. I will try to remember to post the obstacles in the plots as I encounter them. The following plot is four plots to the right and the third plot down from the top of the Lower Green shelf. The 4th plot over on the top row of the lower shelf is not accessible.
This plot contained the following obstacles:
2 - Depleting Poplars: $50,000/each and 20 minutes to clear
1 - Siphoning Cypress: $200,000 and 4 hours to clear
1 - Obsidian Deposit: $400,000 and 20 minutes to clear.
Not cheap at $700,000 coins. The Obsidian Deposit is particularly difficult to select since it is in the lower left corner of the plot and is obscured by the plot to the right of it.