Implants are an excellent alternative to dentures, but they can also be combined to create "hybrid" restorations to help reduce cost. It is important to note that home care and maintenance are integral components of this process to have success and longevity. Plaque, bacteria, smoking and uncontrolled diabetes will compromise healing and stability of the implants so it is important to review hygiene and your medical history with your dentist and become educated on how to clean around your implants properly. If you have just a few teeth missing in small segments, or require teeth to be extracted, these areas can be replaced with implants and crowns provided bone grafting augmentation is done and there is sufficient bone. A single implant and crown (abutment or post if necessary) can range from $1,500 - $4,500, it really depends on the skills and expertise of the restoring dentist, and the oral surgeon or periodontist. On the other hand, you can consider something called a hybrid or "overdenture" particularly for your lower arch if all your teeth are missing or need to be extracted. With this method, only 2-4 implants would be necessary which would reduce the cost per implant to $750 - $2,500 again depending on the clinicians' expertise and type of implant used. However keep in mind this does not include the fee for the overlaying restoration that would be seated over the implants. This has a wide range, again depending on the dentist's skill and knowledge, quality of the laboratory and materials that are used. Hope this helps, good luck!