I live in Jacksonville Florida and have full dentures. What would be the approximate cost to convert them to implants?

The cost depends on number of implants placed, how they are used, and the kind of final restoration.  2 implants and a denture will cost less than multiple implants and a bridge.  Plan on $15-30K per arch to do them well.

There are many variations of utilizing implants to maintain dentures.  I like the snap-in denture best for patients already wearing dentures.  The dentures snap-in and don't move at all if done well.I usually start with lower denture due to ease and maximum improvement  very quickly.  Placing implants is easing but they should not be loaded for a minimum of 3-6 months.   I frequently place four standard implants and four mini implants at the same time.  I leave the standard implants to heal and load the minis day one.Life Changing, you may lose some of minis but what is most important is to have well integrated standard implants to serve you for years.  The mini's take all pressure off standard implants during healing.  While standard implants are healing you can evaluate feeling of snap in denture.  If you prefer screww retained you now have time to plan.  Maxillary denture is supported by the hard palate so mini's are not as valuable unless you can't stand the feel of your palate being covered.  Probably not an issue after 3 years of dentures.

The treatment fees depend on the number of implants placed and the type of prosthesis, snap in or fixed. The most important thing is that they are stable so you can chew.