How do you know you are making the right decision?

I consider myself an intelligent gal.  I can number crunch with the best of them.  But in the end, there are choices that I make (wish I could say WE....but really...it is ME)...that just don't pan out. 

I have spent the past hour crunching numbers again.  Another balance transfer offer came up...this one at 2.99% for 6 months, then at the regular rate of 9.72%.  This is on CC4 (which I just paid off 3 days ago!) which has a limit of $7300.

I am really tempted to go for it and transfer about $6500 (plus the fee) from CC1 (my 19.24% card).  Even at the regular rate....that is half the interest.  If we snowball based on interest....at least that $6500 will be climbing at half the rate it was while we tackle other debt.

Pair this with the idea of applying for a peer to peer lending....where if we could get a rate similar to the 9.72 (say...9.99), it would essentially cut the entire interest from CC1 in half over the course of the loans.  I have said it time and time again...the interest is what is killing us. 

Seems to make sense.  But once again...doubt enters.  What if it isn't right????  GRRR.  I wish I could be more confident in this.  I so really want this noose around our neck gone within 5 years.