You will need a couple years on the job with secure income to qualify for your loan. Knowing that you want to be in the area and in what city is important as well. It takes about 8% of appreciation to break even when you move. In our area that can be about 2 years.
The cloud of uncertainty looming because the landlord could at any time ask you to move out and your rent can constantly go up for some is just too much. For others it's the limitation of making improvements on the house.