I had the opposite shipping problem. It came from Canada to the US.
And it was nearly $10K.
In any case, it worked out fine for all involved. I think you can get additional insurance from USPS, but if you say $700, I believe you. FWIW, if you double pack everything, it should get there without issue. You might try looking at UShip and see if someone is going that way. I shipped a pair of Vandy 3a sigs and they arrived in perfect condition.
Bob
B