Buying land is in my humble opinion almost always a good idea we bought our land/home 33 yrs ago for 149,000 and just turned down 1 million. We could move and live very happy someplace else, but this is home. We got a reverse mortgage a few years ago and don't need to move since we don't want to. The value here jumped very high a few years ago when the train stopped next to the ferry and it became very easy to commute into Seattle and Seattle is going nuts!
The first house we bought I was 17, the next house we bought I was 20. We have always made good profit from buying and selling our houses.
But I have also seen a few folks get burned really badly in some private deals There is one lot here in our neighborhood that the owner keeps "selling" and then rips the new owner off because there is no access to the lot and HE owns the only other lot that they would need to use to get equipment to the lot. There is also a creek that is protected for some critter or something so no building on it. He has done this to many times for it not to be on purpose. So I guess what I am saying is, be careful and check everything with someone who really knows the land use laws etc.