Bookmarklet that opens a Facebook user's Markeplace profile. Get it here: https://bookmarkl.ink/mica/5c9427fab98da699f1fe70fd2730212e

FB Marketplace Profile Bookmarklet.js

//bookmarklet_title: FB Marketplace Profile
//bookmarklet_about: From a user's main FB page, click this bookmarklet for their Marketplace profile
if (location.host == 'www.facebook.com') {
    if (location.pathname == '/profile.php') {
        location.href = 'https://www.facebook.com/marketplace/profile/' + new URLSearchParams(location.search).get('id');
    } else if (location.pathname == '/friends/suggestions/') {
        location.href = 'https://www.facebook.com/marketplace/profile/' + new URLSearchParams(location.search).get('profile_id');
    } else {
        let xhr = new XMLHttpRequest();
        xhr.open("GET", location.origin + location.pathname);
        xhr.send();
        xhr.onload = () => {
            if (xhr.response.includes('userID":"')) {
                location.href = 'https://www.facebook.com/marketplace/profile/' + xhr.response.match(/(?<=userID":")\d*/g)[0];
            }
        }
    }
}