If you are not going to OC,then go for the one which is cheaper because the timings and Mhz won't make a noticeable difference in apps/games,they are mainly important for OC'ng.
If u are going to OC,i would go for the 1066Mhz CL7 due to lower timings
No - I think DDR3 memory will only go down in price. Its possible there would be a small price increase before the end of the year but it wont last. There are not that many people replacing PCs right now and I see no reason to expect a sudden economic burst.