Here's a screenshot from Finnish Post to get some idea about the shipping costs.
one CD and CS usually goes under 100g
two-three CD's and CS goes under 250g
four-five CD's and CS goes under 500g
these are "letter style" packages, so the thickness must be under 3cm. Sometimes when sending 4-5 CD's and CS's it's wiser to send one under 100g + one onder 250g package instead of one under 500g (so that the thickness doesn't go over the limits)
feel free to check more details directly from Post website
NOTE: Because the international shipping rates for LP's are so insanely high, I would recommend to find that same record from some other sellers (with nicer price).