Is it a worthwhile risk to get a Bone Graft/Dental Implant in an Upper Molar site?

Dentist warned me this is an "iffy" endeavor. And costly. Is it worth it to save previous braces/implants from being negatively impacted after the bad molar is removed? The molar cannot be saved. I have to decide if I want to do this before they extract because the bone graft must be done at the time of the extraction...please help me decide what is best.