These Beaded Double Toggle Switch Wall Cover Switch Plates on Amazon.com are modern without breaking the bank! They also have the Single and Triple toggles as well in these same styles.
The double plates start at only $6.80, with free shipping if you have Prime (you can get a free 1-month trial here if you don’t). The triple plates start at $9.80, while the singles are $5. These prices beat Lowes.com (although I did see some lower prices on select plate covers over at HomeDepot.com)