Born and raised in Florida this list in comprised of all my favorite cheap places to go and cheap things to do with my family.
Some places and ideas listed are just one or two hours of fun and some are all day fun!
(All prices,dates and times should be verified before visiting. Please verify with venue websites where applicable)

Ponce de Leon Inlet Lighthouse & Museum
4931 South Peninsula Drive - Ponce Inlet, FL 32127
 

ponceinlet.org

As the largest Lighthouse in Florida this lighthouse is 203 steps to the top.  Although built in 1887 it is now restored and labeled a National Historic Landmark. The view from the top is so beautiful and satisfying. Pictures up there mark the fact that you made it to the top! There is also an entire self guided tour through exhibit buildings and a Garden/Nature Walk. When you have taken in all the sites drive a couple miles back towards the beach and spend the day.

Personal Recommendations:
Arrive when it opens
Climb the Lighthouse First
Take lots of pictures from the top!
Try to spot Nelly the resident Lighthouse Cat
Use the Winterhaven Park Beach access. It's FREE Beach front parking. Offers restrooms, showers and a boardwalk to the beach.

Making our way back down from Ponce de Leon Inlet Lighthouse

Hours of Operation:
The Ponce de Leon Inlet Lighthouse and Museum is open to the public seven days a week with the exception of Thanksgiving and Christmas Day.
Normal Hours of operation are:
Sept 2, 2014 - May 22, 2015: Open from 10:00 a.m. until 6:00 p.m.
(last admission at 5:00)
May 23, 2015 - Sept 7, 2015: Open from 10:00 a.m. until 9:00 p.m.
(last admission at 8:00)

Cost:
Adult- $5.00
Children (11 & Under)- $1.50
Infants (Newborn to 2)- Free with paying adult

Discounts: Check out ponceinlet.org/coupon for special deals off admission