Don't quote me on this, but I recently checked the donation page, and what it looks like is that the donations are now cumulative and depending on how much you donated for the duration of your account you get a certain amount of bonus gold. So essentially, you donated $60 in 3 weeks, your USD to gold should be 3.5 per dollar donated from now on. Until you hit the next benchmark, which is at $100 which will be 4 per dollar until the next benchmark at $250 and so forth.
By this logic, your friend was right in that regard that if you've donated less than $30 then you get no bonus (the base is now 3.2 gold), but according to the new donation page, your cumulative total of ~$60 should take you over that benchmark and you get an extra .3 gold per dollar donated.
Not sure when this was added, but I like it. (Noticed reskin notice is gone though)
