yes Target employee discount and redcard discount stack making a Disney Gift Card $42.75, these can also be stacked with the pharmacy rewards discount (5% off coupon after 5 prescription fills) and any coupons ($5 off a $50 purchase, $5 off $75 purchase you sometimes get printed out at the cash register)
you can buy Disney world tickets from their website but can only use one gift card at a time and they only come in $50 increments so you will do better buying them at Disney world where you can use as many as you like.