Bob,
West leases 100% of their aircraft and East leases 2/3 to 3/4 with the rest mortgaged (EETC's).  So at the end of the day, cost of acquisition is relatively negligible.  Buying, no matter whether the plane is then sold/leased back or mortgaged, does tie up money for a while because of deposits/progress payments.
As I think someone already said, the 175's to Republic was the cost of getting rid of 20 of Chataugua's E145's - at least that was the rationale given.  The sad part is that those 30 175's (with no F/C) going to Republic mean potentially 30 fewer 190's (with F/C) coming to mainline.
Jim