It does seem low, doesn't it? It might add up, that's a bit less than 20,000 2 million dollar missiles, and a lot of it is actually going to be on labour or other things. It is a more impressive figure when you consider how long this has been going on.

Not to mention, the weapons being used are niche and pretty hard to replace on any reasonable timeline. It's not the same as expending the same value in concrete or grain.