phpvms/app/Database/factories/FareFactory.php

<?php

use Faker\Generator as Faker;

$factory->define(App\Models\Fare::class, function (Faker $faker) {
    return [
        'id'       => null,
        'code'     => $faker->unique()->text(50),
        'name'     => $faker->text(50),
        'price'    => $faker->randomFloat(2, 100, 1000),
        'cost'     => function (array $fare) {
            return round($fare['price'] / 2);
        },
        'capacity' => $faker->randomFloat(0, 20, 500),
    ];
});