Should I pull the trigger?

[Dustin Leon]

I am new to REI and have the opportunity to buy the house I am currently renting. This would be my first property. It is a 768 sq ft home 2 bed 1 bath. With a 30yr Conventional and 3.5% down the Mortgage, interest, PMI and Taxes would be roughly $420 at a purchase price of $55,000 with the owners paying any closing cost. No realtor involvement. I currently pay $650 for rent.

Does this deal make sense or are there other factors I should be considering? I would remain in the home for maybe the next 9 months and then look to move to a bigger home. I am married with a daughter who is six who complain that they are often cramped in this small of a home. 

Fire away with any questions I will not be offended by any help or constructive criticism.

Thanks ahead of time!