Sorry, I could not really find better forum to contact regarding the donation cost. Since I wanted to cover the processing fee I selected the bank transfer expecting that this option would leave the most $ in the foundation's pocket (other online payments skip the fee if this option was selected). Yet my donation to Mozilla seemed to incur substantial fee (in additional to higher risk of such transaction). Why so? Maybe the donation page could use some extra explanation to guide payment selection step. I'd sure would use other more secure and convenient means had I known that. thanks