Untitled

<!DOCTYPE html>
<html>
    <body>

        <form method="POST" action="dados.php">
            <select name="taxas" required>
                <option value = "Selecione" selected>Selecione</option>
                <option value = "0,00">0, 00</option>
                <option value = "+0,25">+0, 25</option>
                <option value = "+0,50">+0, 50</option>
                <option value = "+0,75">+0, 75</option>
                <option value = "+1,00">+1, 00</option>
            </select>

            <button type = "submit">Enviar</button>

        </form>
    </body>
</html>

<?php

echo $taxa = $_POST['taxas'];