You can't really rely on those figures until you read the fine print. A lot of the ads will say that this refers to a monthly payment based on putting 20% down payment down and having XXX credit score. Also, those figures don't include property taxes, homeowner's insurance, and mortgage insurance.
As Dan said, these types of homes are often not turn-key (ready to be lived in) and they normally need a lot of work.
With all that being said, that doesn't mean you can't find a nice starter home after you graduate that is affordable.
In order to qualify for a mortgage, lenders will look at your income/employment, credit (your history, score, and monthly debts), and the amount of money you have as a down payment. You'll need to have a stable history of employment. They look at your last 2 years and you either need to be employed during that time or in school getting educated for your current job. You'll need to have some credit established - preferrable 3-4 accounts with at least a one to two year history of on time payments. And finally you'll need to have money to put down for a down payment and to cover closing costs.
Hope this helps!