There are a lot of posts on the web about the economics of Farmville. Mostly they are helping you decide which crops make the most sense to buy with your Farmville Cash. What if I want to buy Farm Cash? What is the most cost effective and cheapest way to buy Farmville Cash?
Farmville offers multiple ways to buy Farmville Cash in multiple denominations. It get a bit confusing. Here are your payment options; Visa, Mastercard, Discover, Paypal, Amazon, Dao Pay, Spare Change, Boku, and Zong. On top of that across all those payment options there are lots of denominations you can pick from, 2-500. Here is a spreadsheet of what I found.
* I rounded a tiny bit so $1.99 becomes $2 and so on.
**Since I am not on an unlimited text messaging plan I added a little extra for services the use SMS like Zong and Boku
Looks like your best bet is to pay for Farmville Cash is with a credit card or Paypal unless you only need a few Farmville dollars. No real surprise considering how expensive it is to go through the more obscure third party platforms. Its interesting that Farmville lets users pay the higher amounts with Boku. Usually it makes since to use mobile payment systems for smaller amounts because the cell carriers take half the money.