Unless you can find at least 1/2 acre zoned for residential, I don't think there's much you can build on it that will generate a decent return. Builder like to keep land at 20%-25% of cost. So, a $200,000 1/2 acre, will need to sell for $800,000 to keep that ratio. I don't see that kind of demand coming back for a while.
On the positive side, buy and hold and it will increase in value over time - lots of time.
Short term raw land remains flat or depreciating right now. There's too much supply for the handful of buyers.
Long term, East Cobb would be an EXCELLENT investment. As another answerer said, there are no more land being made. ;)
My thinking on this? - Raw land by itself is unproven and only as valuable as what you could potentially put on it. Essentially buying raw land for investment is speculation, by definition. It might be smart speculation, but it is still speculation. If the land has a specific purpose (which could change in 10 years, check the land use maps) then the value is related to that purpose - ex: commercial land, c-2 Convenient Store.
The land is "depreciating" or flat, because you have to develop the land to make it a valuable investment. Most companies are not expanding and are not taking development or construction loans at the current time. East Cobb has room for growth but has a certain level of saturation that makes it less desirable than another area. -- this is where you get into specifics for each property.
Essentially, if no one is building new businesses or homes, then the land people build on does not increase in value.
To accurately gauge that I'd need to know location, present use, highest and best use, trends in the area, size of the lot, terrain, cost to prepare the land for it's intended use, availability of utilities....blha blah blah
The short answer is it depends. Drop me an email with more info and I'll give you a thumbnail, my office is right on Roswell Road and I'm appraising/selling every day right here.
Hank Miller, SRA, ABR
Associate Broker & Certified Appraiser
Prudential GA Realty