Ya, Element 5 is pretty dicey, and I don't know why Reallusion doesn't tie up with somebody else. There are more threads in this forum complaining about Element 5's calculations.I remember when I was fresh to Reallusion and bought my first iClone from Daz, the money charged seemed so ridiculous that I raised a row at the Daz forum, mistakenly thinking that it was Reallusion's fault.
After a round of letters with the sales team it became pretty clear that it was Element 5 using the exchange rates against me, converting to Indian rupees when that was good for them and to USD when that was good for them.
After that row, it seems the automatic calculation and offer by Element 5 to pay in my local currency has gone away thankfully.
Now, I always stay careful about selecting USD as the currency to pay in from the top right hand corner, and at least the overcharging has stabilized to a great extent.
Don't know whether this relates to your problem, just shared my experience.
Regards
Surajit