Use currency symbol in single event meta

add_action('tribe_events_before_view', 'use_currency_for_event_cost_meta_field');

function use_currency_for_event_cost_meta_field() {
    tribe_set_meta_value('tribe_event_cost', 'tribe_get_cost_with_currency', 'callback');
}

function tribe_get_cost_with_currency() {
    return tribe_get_cost(null, true);
}