Hmm the only thing I did was to go the UltimatePay site and registered. Just giving them my email address and deciding on a password.
Then on my SE account I clicked the "add Crysta" button. I selected UltimatePay and it let me pick a paymethod. it asked for specifik data like address and then it let me use my own paymethod and I was done.
The first time I bought 500 Crysta and UltimatePay charged 5,35 euro ish
The second time I bought 1000 Crysta and UltimatePay charged 10,35 euro ish
I got 2 mails each time:
SE saying I bought for 5 / 10 euros of Crysta.
UltimatePay saying I bought 500/1000 of Crysta (guess hiding the 0,35 charge unless my bank charged me for using their online services)