Unfortunately, it does not matter if you are buying a $50,000 home or a $500,000 home....a pattern of overdraft fees can be an indication of late pays.
Please make sure that you are well prepared for home ownership. I am concerned that you are already spending most of the money that you make. When owning a home, you will have several other additional, monthly expenses that you may not have as a renter. Examples would be: trash, water, sewer, electricity, gas, cable/satellite TV, etc. Those costs are above and beyond your monthly mortgage payment. Analyze your spending habits and prepare a budget. Please make sure that you are in a position and have the ability to cover the additional expenses of owning a home. Talking to a loan officer can also help in determining that ability.
Best wishes to you!