1) an implant is usually your BEST option but so is an Audi or Mercedes. If you absolutely cannot aford this at this time (and I mean priorities straight- not that big screen TV you planned on) there are temp measures that can be done. That means however, something removable or a space maintainer to hold the back molar where it belongs. Once it moves forward, you have a whole 'Nother problem on your hands! Again ,this is a temporary fix only. I can tell you I do it all the time (esp in a rural area-but usually my patients decide later when they can do it and thats OK)
2) the implant or the fixed bridge is the final solution. That is, if you have a good solid tooth behind the space to anchor the bridge onto. (Yes, I LIKE to end my sentences with a preposition!!!) Otherwise, the implant and implant crown is the only option. Will you die without this tooth? NO! However, you will discover the domino effect- I mean a bunch of of other problems that are a direct result of losing that tooth!
3) as dentists, we are NUTSO CRAZY about saving teeth! I call it Herodontics! But after 20+ yrs of doing this shtick, I can honestly say if I give up on a tooth, you are wise to also. If a second opinion makes you feel better or if you just don't feel like you have been given all the options, find someone with a lot of experience or someone your kids go to school with. (there's that preposition again!) Unfortunately, I have a feeling they are going to tell you the same thing. Just don't be dragged into treatment (root
canal,crown that is not going to have a reasonable lifespan-i.e. how long until it fails?) just because you think it is cheaper, easier,etc,etc!
Good luck and DO NOT spend any money on useless dental insurance at this point!