That's interesting. Then again, I was looking at smaller plots; to build on, I'd want at least 1 acre (I'd go smaller in a pre-built neighborhood, maybe 1/2), but I'd probably be priced out of 5 pretty much anywhere. While there's not much between 540 and Falls Lake, it doesn't look like there's anything available for less than $200k. Meanwhile, on the south side of town, there are a lot of listings under $100k. Right now, there's an acre on Lake Wheeler that's only asking $79k. The closer you get to Garner, the cheaper they are. Of course, those are potentially in the path of 540, which is probably keeping their value low until that's sorted out.
Granted, I haven't actually been out to any of these except for a couple of places near Wake Forest, but that's at least how I formed the impression I'm under.