>>45605975before you do, really look at the edges, cards should only be graded if they're nearly flawless on the back, because we can't see little scratches here and there that happen that make cards 9s. Also if you can try to check centering, it's important for the grade. If those check out and not a single sign of damage exists, it's worth it IMO, 1st edition is rare.
But you're in germany, I think shipping costs are gonna be a real bitch for you. If you think you have all 10s, you're probably looking at over a grand for total cost, yes. But if they're all 10's you're gonna get back 10 grand easily.
Getting grades for 9s is much safer IMO, you spend less and that way if one or two come back a 9 and you really think it's a 10, send it back for a regrade.
Your location fucks you a bit though.