Hahaha you should realize since your dumb ass is new to this forum, that NOTHING is overpaid here (for example, your tag and $10-$35). You'll be lucky to get $5 for your weak booster.
And no, you don't know anybody that's still selling Slayer boosters for $60. Maybe they did one or two years ago, but not now... especially if they're Silver and the Gamertag is of no worth.