I've been purchasing diamonds for a few months now and I recently unbinded from Facebook. I noticed that the diamond packs are different. Does everyone know about this?
These are my diamond options if I'm logged in through Facebook:
And these are my diamond options if I'm logged in through unbinded browser:
The exchange rate would differ by country, but at the time of this post, the US purchase for a 1350 pack would cost me $15.57 USD. That is a difference of $0.41 for an extra 337 diamonds. On the other hand, the Facebook option might yield a better deal depending on your country's exchange. (I'm not familiar with other payment options, but PayPal converts the exchange before your final approval.)
Before purchasing your next pack, unbind your account from Facebook and compare. Unbinding your account allows you to play with or without Facebook. If you are binded, then you can only play through Facebook and you can only purchase the Facebook option.