Help :(

On Thursday, I had to get a molar tooth extracted on my bottom left in the back because it originally cracked and I had to get a root canal. The only issue was the root canal was gonna cost too much so I chose to do a tooth extraction instead since it was hurting I got it taken out however the question that I had was should I do a bone graft instead because I can’t really afford a dental implant I heard that bone graft should be cheaper. I just wanted some opinions and advice. I really wanna prevent jawbone loss as much as possible since I’m 21 and I know I have to do better at keeping my dental hygiene so if this doesn’t happen again, what would your advice be?