I don't think I'd do it. At least, I'd think very, very long and hard before getting a house at full price with the intent of selling it without improvement for 20% profit, within a year.
You could be right, of course, but speculation is pretty risky. I don't think I'd do what you have in mind, unless there's another exit plan available? For example, do theses houses meet the 50% rule of mortgage vs rent? In that case, you could rent out a house if it doesn't appreciate as expected.
It might be much wiser to search for foreclosures, REO deals, and other deals in the area if you really want to go for it. Buying a home at full price so that you can sell it for 20% more after a year, without doing any improvements... it sounds way too hopeful.