There are many advantages in using a realtor for buying your house, not enough space to mention them all here:

A good realtor has definitely a good negotiation skill and can get them a better price; no matter if they sell with her or to buy! 

They don`t have to be worried about the paper works!

MLS is the biggest Home searching tool and only the Realtors have access to it, plus realtors have access to off market and coming soon houses which the Buyers are not aware of!!! A big advantage! 

The Market knowledge of a realtor can never be compared with a buyer knowledge!!!

Most realtors have been fully trained about the house reports and inspections so what a buyer might miss in the reports, will never be missed by a good Realtor!

Most importantly you their company can pursue the legal actions and file the lawsuits for them if something comes up!

At the end, they LOSE NOTHING and get all the services absolutely for FREE! So why NOT?

If you're well versed with the laws and customs of your state and municipality, you know how to negotiate strategically, read and understand contracts and have reliable connections within the finance and title/settlement industry and have closed on several homes before then you might not need a realtor but I'd still suggest using a real estate attorney at the very least, in the unlikely event that you choose not to use a Realtor. However, a good Realtor will get the deal done effieciently and at a cheaper rate than a Real Estate attorney.

So, in short, just use a Realtor…from the beginning, if possible…before you sign anything or make any verbal agreements!