You need to get the terms as set by WP for the post
https://developer.wordpress.org/reference/functions/get_the_terms/
$terms = get_the_terms($post->ID, 'repair_type');
This will return an array containing all of the selected terms. You need to loop over these and get the field from the term
if (!empty($terms) && !is_wp_error($terms)) {
foreach ($terms as $term) {
$repair_price = get_field('repair_price[, $term);
}
}