It's super tricky as we aren't buying a tangible product, rather we are paying for a license to use some software. I believe that the CE bundle is technically a free bonus on the side of that license regardless of the price premium?
Grey area for sure! One thing I am fairly certain on is that the EU orders will be shipped from the London office, thus handling and shipping expenses can't really be used as justification.
Given the weak euro, doing some homework on this could be worth £30-£40, well worth it for a few emails methinks!