I wish I would have known that unlocking an Orange X10i was so freaking expensive before i bought mine, lol. I couldn't get it done via Orange as I'm not a customer (and on a different continent)...
I had mine unlocked via htccode.com, also 40$ (oof, they raised their rates to 50$!). It seems it's the same type of unlocking that cellunlocker.net uses. I found a different company to unlock the x10 for 35$ (code unlock) but after a month of waiting I had to fight them to get my money back.