If you are only 2, then you could use disney transfers...Renting a car is probably the cheapest option though..My dh hates to drive like this on holidays, so we use a car service, from MCO to hotel (cocoa beach) and then from the port back...It is usally about 200$ plus tipping, works out to less than their transfers..
HTH
check out dcltribute.com it has great info about this.
GET UP TO A $1000 SHIPBOARD CREDIT AND AN EXCLUSIVE GIFT!
If you make your Disney Cruise Line reservation with Dreams Unlimited Travel you’ll receive these incredible shipboard credits to spend on your cruise!