Hello John,
The cost is US$275 for both boxes (total of 100 5x7 sheets). Shipping included in that price would be via Canada Post/USPS, tracked and insured (PO tells me it is insured for loss, but not usually damage).
Regarding x-rays, I understand that a very small percentage of parcels get x-rayed, anything suspicious of course (not sure if labeling "FILM - DO NOT X-RAY would attract unwanted attention?), then some mail at random, so it is perhaps unlikely to be x-rayed but there is no guarantee. I've gotten film from B & H, both regular mail and UPS, and so far it's always been fine, though perhaps I have just been lucky. If you are familiar with a means of shipping that does not x-ray let me know.
I am not sure about the UV blocking layer. Checking around it sounds like Tmax100 has the UV blocking but not Tmax400?
Let me know if you have any more questions.
Regards,
Peter