@Mame,
I have a mouth full of both. I had the root canals done in the early 80's so they were much less expensive than today. The work was done by an excellent dental surgeon and I never had problems with them until they aged as much as the rest of my body.
After 30 years, some of the teeth those root canals were done in have weakened to the point that they've broken off at the gum line. In one section of my mouth, I have a permanent partial denture in place of those teeth.
Other teeth have just died on their own after being covered by fillings or crowns for most of my life. When they started crumbling and got to the point that they abscessed and caused pain, I had them pulled.
The rest of my teeth are about 15 years overdue for a second replacement of caps, crowns and fillings that I can't afford this time around. When it is their time, they too will be pulled and I'll eventually have full dentures.
I have soft teeth and have had dental problems since I was in first grade. My parents probably could have put several people through college with the money they shelled out for it. When I was paying the co-pays from my employer's dental insurance, I probably paid another $15k just in co-pay for my first set of replacement caps, crowns and fillings in the 80's.
So, in addition to deciding whether or not to pull or have a root canal, you'll also need to consider whether you'd want some sort of denture to fill the gap or leave it as is.