Where in Florida are you, I have many companies that can help you. Culligans $150 per year sevice is actually not bad at, but the initial cost will negate this as being a good price. I guarantee you the price they quoted you is highly negotiable, but even so, consider getting some other prices. According to my calculations, you should use 8 bags of salt per year, considering the delivery costs, etc. that is $15 per bag, but you will also never have to pay for a service call, parts, maintenance, etc. Please move forward with an offer like this with extreme caution, read the contracts carefully, and push them hard with questions. Get anything they say in writing, and not from the sales guy, but from their regional manager. Buyer beware on something like this.
I would also recommend researching the long term financial viability of any company that is offering a long term contract.