We witnessed a slightly drop in module prices specially for high capacities ( 8GB ) due to the low demand worldwide, low capacities kept their prices stable.
“Led by Samsung, global DRAM bit supply growth will reach 24.2% in 2014 compared to a growth of 23.1% a year earlier. But DRAM bit supply is set for slow growth in the future as current bit supply growth has been driven by upgrades of manufacturing processes rather than by the installation of new production” According to Digitimes Research.
I advise to keep maximum one to two weeks stock for 4GB and 8GB modules, while for 2GB you can keep more as the prices reached the limit down.