Potchergirl,
You can find a lot of average mortgage and home value info at
27713 Zip Code (Durham, North Carolina) Detailed Profile - residents and real estate info. The 27713 zip code is SW Durham (where I live).
Since your husband will be based at UNC, and Chapel Hill can sometimes be a bit high-priced, I would recommend SW Durham for the following reasons:
1) If you want access to museums and more points of interest for field trips, you would do better to be on the eastern side of Chapel Hill so that you could access historic Durham, the museums and attractions of Raleigh, the potteries of Seagrove, etc. I-40 offers great access to most places in the Triangle.
2) Shopping in SW Durham is amazing easy and convenient. There are stores in any price range. (We even have a new Family Dollar opening up in our little grocery strip down the street, and the Homestead shopping center still has a Roses, so don't think everything is as posh as the Streets at South Point!)
3) Even though you're home schooling, there are a lot of families with young children living in 27713 (the elementary schools - Creekside, Southwest, and Hope Valley - are solid), so your kids should have plenty of neighborhood friends.
4) You can usually get more bang for your buck in Durham.
As for homeschooling, I think the group in Chapel Hill has a high profile. Here's a link that you probably already have, but I throw it in anyway. NCHE: North Carolinians for Home Education (broken link) You should be able to get some pointers there about how to join up with others wherever you may settle.
Best wishes in your search!