A best bet is this 18-Total Carat Weight Couples' Two-Tone Name and Birthstone Diamond Ring (pictured) for $69.99 before the above coupon, $52.49 after. With $5.99 for shipping, that's $68 off list and the lowest total price we could find. It features two marquise-cut crystal birthstones and two engraved names (up to 10 letters per name).
Spending less than $50? Coupon code "VDAY213" cuts 20% off orders of $40 or more (these coupons don't stack).
Couples Two-Tone Name & Marquise Birthstone Diamond Ring is also available at these stores