help! repeat root canal or extraction ??

I've notice a few other posts similiar to mine but my problem seems to be unique. I WOULD APPRECIATE SOME EXPERT ADVICE !!!!!
I had a root canal done 2 yrs ago which was successful - or so they said. Fortunately at that time I had dental insurance so the cost was shared between me and my insurance carrier. Now, here it is, 2 yrs later, the same tooth is abscessed again and I no longer have dental insurance. I saw my dentist 2 wks ago before my tooth abscessed and he said I would either have to have another root canal or have the tooth extracted, if it was cracked. That RC was $2000 which I can't afford now but I would like to know what other options I have. Is the price of an extraction comparable to a RC? Most say that if the tooth is extracted then I would need a bridge but my husband has had 2 missing teeth (one upper molar on each side)for the past 30 yrs and his teeth never shifted. I am 53 yrs old now. What are the chances of my teeth shifting now? Also, why would a specialist NOT be responsible for a RC tooth getting infected again? I would think they would have enough integrity to know if a job was well done and/or be responsible for a portion of the bill if a RC has to be redone. One website I read said that repeat RCs are more complicated and more expensive than the first one. Are specialists intentionally not doing a sufficent job the first time around just for more business? I'm sorry if I sound skeptical but I just don't understand why I should have to pay for a procedure a second time around and why the RC on this tooth (2nd molar from back,upper left)only lasted for 2 years. And.... if the tooth really is cracked, isn't there a chance that it can be saved with bonding or something else?

PLEASE - I WOULD REALLY APPRECIATE SOME EXPERT ADVICE AS I AM IN A LOT OF PAIN NOW AND NEED TO MAKE A DECISON QUICKLY. THANK YOU.