I do agree that NT is a spot where the Rams could use a new/better starter.
However, I don't see it as the top priority in the sense that it would be the position where I'd spend a ton of FA$ or a first round draft pick. The reason is that, in Wade Phillips' D, the NT could be a 2 down position. As such, it can be filled with a "non-star" (i.e. the kind of guy who can be drafted in the 3rd/4th round).