Amnio - deciding whether or not to have one

Decision, decisions...  I have spent much of the last 2 weeks waffling back and forth between having an amnio or not.  We had a great nuchal ultrasound at 13 weeks.  Baby looked great, very low risk for all the age-related risks (e.g, Down's, Trisomy 13, 18).  I thought if I got a good ultrasound that I would feel ok proceeding without more invasive testing.  And then I start reading stories about people who had normal ultrasounds, but their babies were born with horrible conditions.  Some lived a few days, some a few months, one as long as 3 years.  I know people feel differently about these things, but for me, if the baby had a condition not compatible with life, I would rather end things now than put myself and our whole family through that type of heartache.  That's part of the catch, though.  We can do an amnio and find there is an unbalanced chromosome situation, but if everything still looks fine on ultrasound, would I really be willing to terminate?  I am not so sure.  The doctors tell me if the baby is unbalanced, and physically looks fine, they will definitely have mental issues, but they cannot tell me how severe.  So how the heck am I supposed to make a decision??

Here is more of what I have learned in my research and what weighs in on my decision:

• Amnio miscarriage rate is no longer 1% as published is so many places.  It's more like 1 in 200- 1 in 400 and less if the doctor is experienced.  My doctor's office indiciated that they quote 1 in 500 and that is very conservative.
• My doctor's office feels that any miscarriages associated with amnios are likely because there is already an underlying infection or complications present.  They do an indepth screening and won't perform the amnio if conditions are not ideal (they even question having a cold).  
• Cost - we are able to get a discount, but even then the amnio will cost north of $1500 which we pay out of pocket.
• Peace of mind - something in my gut tells me everything is fine with this baby.  It's my head that is getting in the way - the "what if's."  One thing I would LOVE is to be able to have assurance that this baby is chromosomally normal and maybe I can learn to relax and enjoy this pregnancy.  So far, I feel very guarded and I know it's my own way of emotionally protecting myself.
• On the flip side of peace of mind, I have to ask myself how I will feel if I do miscarry as a result of this procedure.  Will I blame myself?  I honestly cannot put myself in the proper frame of mind to answer that question.  I truly don't know and every time I try and imagine it to see how I would feel, I just can't get there.  As a sidenote, you can also have complications like amniotic fluid leaking and be put on bedrest.  I cannot afford to be on bedrest for the next 6 months!
• What I will do with the results.  Many people do not choose to do amnios because they know they will not terminate regardless of the outcome.  There are others that know they won't terminate, but want to know, so they can research and be prepared for their baby's condition.  I actually read some beautiful stories about Down Syndrome babies and how their mothers felt so prepared in knowing and told the hospital staff when the baby was being delivered that this is not a sad occasion, but a wonderful, wonderful thing, and this is their baby - so they didn't want anyone being in shock or upset at delivery.  For me, I truly don't know what I will do with the results.  The only way I can see terminating is if things are REALLY messed up (way too much or way too little chromosome material) and if the ultrasound is showing there are major problems.  Outside of that, I think I will have a very difficult time.  As a sidenote, I have also contemplated the fact that I will be 17 weeks by the time we get results, which is no joke in terms of terminating at that point.  There is apparently only 1 doctor in my state that does pregnancy terminations beyond 14 weeks.  
• My doctor's opinion - the genetic counselor feels strongly that I should do it.  She had me consider the impact to my whole family (my existing 2 children) and the peace of mind I will feel if everything is ok.  I flat out asked my doctor his opinion (he is VERY busy and very skilled at what he does, but doesn't usually weigh in on decisions like this)....I could tell from his body language that he didn't feel it was necessary.  he felt that I would have either miscarried, or something would be showing wrong on the ultrasound with growth being delayed or other issues with physical development.  So, when you flat out ask the doctor, and you don't get a warm and fuzzy...then what??  

With all of that said, I am leaning toward doing it, but I am scared.  Really scared, mostly of making the wrong decision.