Very expensive. Of the Orlando airport companies, I have found Dollar usually has the best rates. However, the rates jump all over the place. So, the key is to book the cheapest thing you can found now and periodically check back between now and August. At some point, you will get offered a ridiculously low rate, like 100-150 for a compact for a week. Simply cancel you original and rebook. It tkes a couple clicks online. Also, register for the free loyalty program of the company you choose. Skipping the rental counter and heading basically straight for your car is a huge time saver. Last thing, travel sites like expedia or orbitz are good for getting a general idea on rates, but the car company sites usually have "unadvertised" rates that are lower.