The choice of location would have a lot to do with what's important to you... view, community amenities & restrictions etc.
You can often get a lower price per square foot if you're willing to purchase an existing home over building new. Depending on your lot and the topography (which can often be quite challenging in the Canyon Lake area) it can often be quite expensive to build. If you don't mind a home that needs some updating or minor repairs you can often get a really nice home for a very good price.
As far as I know HEB has no plans at present to come to Canyon Lake, however Brookshire Brothers (http://www.brookshirebrothers.com/) is planning a store near 306 & 3424 on the north side of the lake with a projected opening in early 2014.
You can go to our website (www.RelianceRR.com/CarlandEllen) and set up an automatic search to look for properties or if you would like more information about local builders please feel free to contact us, we'd love to help you find just the right property for you!