If the boat was poorly maintained there may be many problems -- as Auzzee notes. It is a relatively simple task to keep a wood mast in good shape indefinitely but if they have let rot there may be significant repairs needed. Repairs to wood masts are actually quite simple for a person who has a mast bench (for big repairs) or is a knowledgeable wood worker with spar experience. In Florida there are often problems with termites as well as rot -- if termites are the reason for the mast to break (break is a big word!) Do you know why it is broken?
Our wood masts are round but were built up with a box construction (like yours) and they are 85 years old. They have been repaired a couple times over the years and when we purchased the boat (2006) we re-did a couple repairs just to make sure they were properly done. One was, the other was not. It's not rocket science but the spar makers or wooden boat repair people with the experience to do the job do tend to charge a pretty penny for the work to be done. Whether it is worthwhile to rebuild or repair the masts yourself comes down to your patience and space as well as tools, existing woodworking experience, etc.
The whole 70's and 80's era of "leaky teaky" decked fiberglass boats leaves one with a lot of question...
If you're considering purchasing this vessel, you know it is STILL a buyers market and you are likely to find a boat with good spars easily.