They've already dropped significantly throughout this year. Used to be that DDR4 cost 1.5x or more than DDR3 for the same capacity, while now we have (roughly) price parity. I wouldn't expect major drops to continue, but then I tend to be pessimistic about these things. RAM production is a low-margin business, so the only way prices will drop significantly is if production process improvements allow them to make the RAM cheaper. This happens step by step, but it's not a fast process.