Possible explanations include:
1- Presidents Day Weekend
2- Beginning of Spring Break for some (and the beginning of high season)
3- Speed Weeks at Daytona with major events on Feb 13, 14 and culminating with the Daytona 500 on Feb 15th. Hint: Try to avoid I-4 in the Daytona Beach area before and after a race.
Generally, car rental prices in the Orlando area are very reasonable.